NASA TECHNICAL
TRANS L ATI ON
co
is*
I NASA TT F-228
<s-
/
□
er
CP
tr
ru
3
n
AVIATION AND SPACE MEDICINE
V. V. Parin, Editor in Chief
Akademiya Meditsinskikh Nauk, SSSR,
Moscoiv, 1963
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION • WASHINGTON, D. C. • DECEMBER 1964
TECH LIBRARY KAFB, NM
lllllllll
DDbablE
NASA TT F-228
AVIATION AND SPACE MEDICINE
V. V. Parin, Editor in Chief
Translation of "Aviatsionnaya i kosmicheskaya meditsina"
Akademiya Meditsinskikh Nauk, SSSR, Moscow, 1963
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
For sale by the Office of Technical Services, Department of Commerce,
Washington, D.C. 20230 - Price $7.63
CONTENTS
Page
Results of Physiological Investigations on the Spaceships
Vostok 3 and Vostok 1* 3
I. T. Akulinichev, R. M. Bayevskiy, V. Ye. Belay,
P. V. Vasil'yev, 0. G. Gazenko, L. I. Kakurin,
A. R. Kotovskaya, D. G. Maksimov, B. P. Mikbaylovskiy
and V. I. Yazdovskiy
Changes in Some Indices of Respiratory Biomechanics in
Sick and Healthy Persons under the Conditions of Hypoxia 5
V. N. Alifanov
Changes in Bioelectric Activity of the Myocardium in Man after
Exposure to Hypoxic Hypoxia According to the Data of Vector
Analysis 9
V. N. Alifanov and L. M. Zemesheva
Biotelemetry on Manned Space Flights 12
G. V. Altukhov
Some Problems in the Psychology of Flight Activities Ik
B. S. Alyakrinskiy
Some Problems in Ensuring the Radiation Safety of Space Flights 18
V. V. Antipov, V. G. Vysotskiy, B. I. Davydov, N. N. Dobrov,
V. S. Morozov, G. F. Murin, M. D. Nikitin and P. P. Saksonov
Effect of Different Partial Pressure of Oxygen and Environmental
Temperature on Regulation of Temperature Relations in the
Organism 20
I . I . Antonov
Medical Service for the Civil Air Fleet of the USSR 2k
A. S. Asribekov
Labor Hygiene in the Spraying of Chemicals from Civilian
Airplanes 26
T. A. Asribekova
Pharmacological Prophylaxis and Therapy of Airsickness 28
Z. A. Astakhova, Ye. P. Belogortseva, M. D. Kruglik and
P . I . Syabro
mi ill ■ 1 1 ill mil ii i mi i ii i mill ii ii ii iiiiiii in pun
Page
The Dog Spleen Response to Lateral Acceleration 32
Yu. I. Afanas'yev
Modern Aviation and Problems in Ensuring the Medical Safety
of Flights 36
A. N. Babiychuk
The Efficiency of Man Exposed to Radial Acceleration and
Breathing of Oxygen at an Excess Pressure 36
V. I. Babushkin and V. V. Usachev
Physiological Reactions to Radial Acceleration 38
V. I. Babushkin, P. K. Isakov, V. B. Malkin and
V. V. Usachev
Transmission of Medical Information over Limited-Capacity
Telemetry Channels Ul
R. M. Bayevskiy
Dynamics of the Elimination of Corticosteroids after Various
Actions kk
I. S. Balakhovskiy and I. G. Dlusskaya
Effect of Accelerations on the Growth of Living Beings h6
V. I. Baranov, A. A. Gyurdzhian, M. A. Lomova, L. A. Radkevich,
L. T. Tutochkina, T. A. Fedorova, L. P. Furayeva, S. S.
Khnychev and N. S. Artem'yeva
Leading Trends in Aviation and Space Ophthalmology k9
V. V. Baranovskiy
Threshold Contrasts and Brightness to Ensure Visibility of
Objects at Wight and during the Day 51
V. V. Baranovskiy, L. N. Meyer and V. V. Preobrazhenskiy
A New Method of Studying the Tendency to Illusions of
Spatial Orientation 53
V. V. Baranovskiy and I. D. Semikopnyy
Increasing Resistance as a Means of Providing Biological
Protection against Various Environmental Factors during
Flight 56
Z. I. Barashova
Respiration and Gas Exchange in an Acute Hypoxic Test 59
A. V. Beregovkin, P. V. Buyanov and V. B. Malkin
11
Page
Effect of Change in the Gas Medium on "Primary Potentials"
of the Auditory Area of the Cerebral Cortex in Animals and
on Some Functions of the Acoustic Analyzer in Man 62
E. V. Bondarev
The Possibility of Biological Objects Growing and Living a
Long Time in a Helium- Oxygen Atmosphere 6k
V. V. Boriskin, P. A. Gul'tyayev and B. M. Savin
Some Aspects of Medical Examination of Flight Personnel 67
K. F. Borodin
Obesity in Fliers 70
I. M. Buznik
Functional Evaluation of Blood Circulation from Change in
Circulation Effectiveness. Value of the Method in Select-
ing and Training Flying Personnel 73
P. V. Buyanov
Functional Changes in the Cardiovascular System after
Exposure to Hypodynamia 76
Yu. V. Vanyushina
Effect of Some Drugs on Tolerance of Accelerations 79
P. V. Vasil'yev and V. Ye. Belay
Structural and Cytochemical Investigations of the Utricle
under the Conditions of Relative Rest and after Exposure
to Accelerations 85
Ya. A. Vinnikov, 0. G. Gazenko, L. K. Titova,
A. A. Bronshteyn and V. I. Govardovskiy
Oxygen Supply of the Heart during Respiration at Excess
Pressure 87
V. G. Voloshin
Ensuring Radiation Safety on the Flights of Astronauts
Yu. A. Gagarin, G. S. Titov, A. G. Nikolayev and
P. R. Popovich 90
Yu. M. Volynkin, V. V. Antipov, N. W. Dobrov, M. D. Nikitin
and P. P. Saksonov
Changes in Cardiac Activity during Prolonged Lateral
Accelerations <$k
A. D. Voskresenskiy
iii
Page
Interrelation of Hemodynamic Changes and Respiration during
Accelerations 97
P. F. Vokhmyanin
Involvement of the Vestibular Apparatus in Regulating the
Blood Sugar Level 100
R. Kh. Gambarova
Changes in the Bioelectric Activity of Different Parts of
the Brain during Exposure to Prolonged Accelerations 102
0. G. Gazenko, B. B. Yegorov, G. V. Izosimov,
Yu. P. Limanskiy, A. N. Rasumeyev and P. M. Suvorov
Anticipating Reactions in Flight Activity 10?
S. G. Gellershteyn
Data on the Behavior and Some Functions of Persons Kept
under the Conditions of Limited Mobility 107
M. A. Gerd
The Physiological -Sanitary Justification for Substituting a
Luminous Substance of Intermittent Action for the Phosphor
Now Used on Airplane Instrument Dials 111
V. Ya. Gilinskiy and A. Ya. Loshak
The Effect of Low Concentrations of Carbon Monoxide on Man
in Pressurized Cabins of Passenger Planes 113
V. A. Gilinskiy, A. V. Chapek, A. G. Kozlova,
N. M. Kulikova and A. Ya. Loshak
Morphological Changes in the Nervous System of Animals
Subjected to Lateral Accelerations 115
B. S. Glushkov
Some Functional Changes in Man after Prolonged Isolation 116
F. D. Gorbov, V. I. Myasnikov and V. I. Razdovskiy
The Main Problems in Investigating Shock Overloads Arising
in Flights on Airplanes 119
S. A. Gozulov and G. P. Mirolyubov
Increasing Resistance to Oxygen Deficiency by Means of
Drugs 121
G. I. Gurvich and K. S. Shadurskiy
IV
Page
White Rat Respiration after Prolonged Exposure to Radial
Accelerations 123
V. I. Danileyko, A. I. Nazarenko and 0. S. Savchenko
Impairment of the Mechanism of Mitosis in Microspores after
Flight on Vostok 3 and Vostok k 126
N. L. Delone, P. R. Popovich, V. V. Antipov and
V. G. Vysotskiy
Qualitative (Stage) Evaluation of Flight Fatigue I3O
Ye . A . Dere vyanko
Psychophysiological Characteristics of Instrument Flying I3U
Ye. A. Derevyanko and N. D. Zavalova
Selection of Individuals for Flight Training I36
T. T. Dzhamgarov
The Possibility of Substituting Helium for Nitrogen in
the Cabins of Spacecraft I38
A. G. Dianov and A. G. Kuznetsov
Excretion of 17-Oxycorticosteroids in an Investigation of
the Efficiency of Airplane Crews on Long Night Flights 1^0
I. G. Dlusskaya, F. L. Kosmolinskiy and N. A. Fedorov
Vestibular Influences on the Smooth Muscles of the Small
Intestine and Blood Vessels after Transection of the
Spinal Cord and Vagus, Cervical Sympathetic, and Splanchnic
Nerves lh.3
A. S. Dmitriyev and Ye. V. Burko
Some Data on an Investigation of Chain Conditioned Motor
Reflexes in Animals after Long Exposure to an Altered
Gas Medium 114-7
G. P. Doronin
Changes in the Capacity of the Central Nervous System
While Learning to Pilot a Training Plane 150
V. A. Yegorov
Change in Back Pressure on the Body and Tolerance of
Respiration at Excess Pressure 152
A. V. Yeremin and V. N. Alifanov
Page
Effect on Man of Prolonged Exposure to Atmosphere with
a High C0 2 Content 155
S. G. Zharov, Ye. A. II 'in, Ye. A. Kovalenko,
I. R. Kalinichenko, L. I. Karpova, N. S. Mikerova,
M. M. Osipova and Ye. Ye. Simonov
Evaluating the Biological Effectiveness of Space Flight
Factors by Means of the Lysogenic Bacteria E. Coli
K-12 U) 158
N. N. Zhukov-Verezhnikov, I. N. Mayskiy, V. I. Yazdovskiy,
A. P. Pekhov, N. I. Rybakov, G. P. Tribulev, P. P. Saksonov,
N. N. Dobrov, V. V. Antipov, V. A. Kozlov, V. G. Vysotskiy,
B. A. Mishchenko, K. D. Rybakova, G. P. Parfenov,
V. V. Pantyukhova, Ye. V. Yudin and Ye. D. Aniskin
Modern Genetics and Problems in Space Biology l6l
N. N. Zhukov-Verezhnikov, M. N. Volkov, V. I. Yazdovskiy,
I. N. Mayskiy, P. P. Saksonov, P. A. Konstantinov,
A. P. Pekhov, G. P. Tribulev, N. I. Rybakov, V. Ya. Kop'yev,
I. I. Podoplelov, N. N. Dobrov, V. A. Kozlov, V. G. Vysotskiy,
N. S. Artem'yeva, V. V. Antipov, B. A. Mishchenko,
Ye. D. Aniskin, Ye. V. Yudin, K. D. Rybakova and R. I. Shupik
Impairment of Protective Mechanisms Following Exposure to an
Altered Gas Medium l6k
V. N. Zagryadskiy and Z. K. Sulimo-Samuyllo
An Investigation of Higher Nervous Activity and Some Motor
Reactions in Man under Conditions of Brief Weightlessness 167
A. T. Zverev and L. A. Kitayev-Smyk
Some Aspects of Hemodynamics in Breathing Oxygen with
High Pressure in the Lungs I69
D . I . Ivanov
Changes in Man's Principal Physiological Functions after
Prolonged Exposure to Low Barometric Pressure in a Small
Space 172
D. I. Ivanov, V. B. Malkin, I. N. Cbernyakov, V. L. Popkov
and Ye. 0. Popova
Hypoxia and Chemical Thermoregulation I75
K . P . Ivanov
The Time Reserve in Steadily Decreasing Altitude I77
L. S. Isaakyan
vi
Page
Evaluation of the Degree of Tension in Pilots Executing
Landings in Various Types of Modern Airplanes under
Ordinary Conditions 179
L. S. Isaakyan
Some Results of a Clinical and Physiological Study of Senior
Pilots of the Civil Air Fleet l8i(-
L. S. Isaakyan, D. S. Kuleshov, A. V. Chapek, V. M. Kozin,
A. N. Ustinova, N. M. Kulikova, Ye. I. Kuznetsova and
A. A. Shishova
A Theory Concerning Gravitational Influences on the Organism 188
P. K. Isakov
Effect of Hypokinesia on Certain Indexes of Efficiency and
Respiratory Function in Man 192
L. A. Kakurin, B. S. Katkovskiy, A. N. Kozlov and
N . M . Mukharlyamov
Obtaining Visual Information during Instrument Flying I9I1
I . A . Kamyshev
Reactions of Astronauts to Brief Periods of Weightlessness 198
I. M. Kas'yan
Pathomorphological Visceral Changes in Animals after
Accelerations 201
M. I. Kas'yanov and G. P. Mirolyubov
Quantitative Evaluation of Operator in a "Man-Machine"
System • 20^
Yu. V. Kiselev
Trace Phenomena in the Central Nervous System after
Prolonged Optokinetic Stimulation 205
V. A. Kislyakov and V. P. Never ov
Changes in Electric Activity of the Cerebral Cortex and
Subcortical Formations in Animals Exposed to Brief
Periods of Weightlessness and Acceleration 206
A. M. Klochkov
Some Sensory Disturbances in Persons Exposed to
Weightlessness 209
L. A. Kitayev-Smyk
Vll
Page
The Body Position (Postural Reactions) of Animals in
Weightlessness 211
L. A. Kitayev-Smyk
Effect of Centrifugal Accelerations on the Venous Outflow
in the Cerebral Blood Vessels of Animals 213
V. Ya. Klimovitskiy
Pathogenesis of Hemodynamic Disorders after Exposure to a
Supersonic Air Stream 2lU
A. F. Kovalenko, Ye. Ya. Kaplan, V. P. Boyarkin and
A. M. Klochkov
Effect of Hypothermia on Oxygen Deficiency at High Altitudes 217
Ye. A. Kovalenko, V. I. Korol 'kov and Ye. A. II 'in
Effect on Brain Oxygenation of Breathing Oxygen during
Accelerations 220
Ye. A. Kovalenko, V. L. Popkov and I. N. Chernyakov
Morphological Labyrinthine Changes in Dogs Exposed to
Radial Accelerations 223
R. Ye. Kogan and S. S. Makaryan
Speech Audiometry as a Method of Functional Diagnosis in
Fitness Examinations of Flight Personnel 227
V. M. Kozin
Effect of Flight Factors on the Adjusting Reflexes 23O
G. L. Komendantov
Some Results of a Study of the Cardiovascular System in
Fliers on Different Flights • 233
S . Ye . Komshalyuk
Histomorphological Changes in Dog Pancreas after Exposure
to Lateral Accelerations 235
Yu. N. Kopayev
The Latent Form of Motion Sickness 238
V. I. Kopanev
Training Man for Space Flight 2*4-0
A. A. Koreshkov
vm
&
.'-^->
Page
Weightlessness from the Standpoint of Terrestrial Physiology 21+2
P. A. Korzhuyev
Development and Preservation of a High Level of Motor
Function as a Problem in the Preparation and Execution
of Extended Space Flights 2*)-5
A. V. Korobkov
Effect of Lateral Accelerations on Dog Lung Histology 2V7
Yu. N. Korolev
Effect of Lateral Accelerations on Dog Kidney Histology 2lj-9
V. V. Korolev
Psychological and Physiological Characteristics of the Work
of Airplane Crews in Connection with In-Flight Refueling 252
F. P. Kosmolinskiy
Effect of Prolonged Lateral Accelerations on Monkeys 25^
A. R. Kotovskaya, P. V. Vasil 'yev, B. A. Lapin, S. F. Simpura,
I. S. Grishina and V. I. Kulinskiy
Effect of Accelerations on Liver Structure 257
Ye . F . Kotovskiy
The Use of Hyperventilation in Selecting Candidates for
Flying School 260
A. K. Kochetov
Principles Governing the Objective Evaluation of the Thermal
State of the Body 262
V. I. Krichagin
Changes in Some Physiological Functions Resulting from
Explosive Decompression 267
A. G. Kuznetsov, A. S. Tsivilashvili and A. R. Mansurov
Changes in Respiratory and Cardiovascular Functions after
Prolonged Exposure to Low Barometric Pressure 270
A. G. Kuznetsov, N. A. Agadzhanyan, Yu. P. Bizin,
N. I. Yezepchuk, I. R. Kalinichenko, L. I. Karpova,
I. P. Neumyvakin and M. M. Osipova
Changes in the Vectorcardiogram of Flight Personnel in
Early Stages of Hypertension 272
Ye. I. Kuznetsova
IX
Page
EKG Changes in Flight Personnel after Prolonged Nonstop
Flights 27k
N. M. Kulikova
Participation of L. A. Orbeli in the Development of the
Problem of Cosmic Physiology 277
A. V. Lebedinskiy
Some Physiological Aspects of the System of Astronaut
Selection and Training 2Qk
A. V. Lebedinskiy, N. I. Arlashchenko, B. B. Bokhov,
Yu. G. Grigor'yev, L. N. Kvasnikova and Yu. V. Farber
The Prolonged Effect of Slow Coriolis Accelerations on
the Human Organism 289
A. V. Lebedinskiy, N. I. Arlashchenko, V. Ye. Busygin,
R. A. Vartbaronov, A. S. Veselov, N. A. Volokhova,
Yu. G. Grigor'yev, M. D. Yemel'yanov, T. V. Kalyayeva,
Yu. V. Krylov, B. I. Polyakov and Yu. V. Farber
Labor Hygiene and Occupational Pathology Involved in the
Work with Centimeter Wave Generators in the Civil Air
Fleet 292
A. Ya. Loshak
The Vibration and Radiation Effect on the Acidifying
Processes in the Brain Tissues of Rats 296
L. D. Luk'yanova
An Electroencephalogram of an Acute Hypoxic (sic)
Hypoxia 297
V. B. Malkin
The Characteristic Features of the Clinical Course and
the Expert's Opinion of Flight Personnel Afflicted with
Stomach and Duodenal Diseases 3OI
Ye. T. Malyshkin and B. L. Gel' man
On the Diagnosis and Expert Medical Opinion of Flight
Personnel Afflicted with Atherosclerosis 3O3
Ye. T. Malyshkin, N. A. Gol 'din and V. M. Tolstov
Vestibular Reactions under the Effect of Various Angular
Accelerations 305
S . S . Markaryan
x
^ss&
Reactive Changes in the Inguinal Lymph Nodes under the
Effect of Various Overloads on the Organism of Dogs
Yu. V. Mashkovtsev
The Dynamics of the Morphological Changes in the Cerebral
Cortex of Dogs Following the Effect of a Transverse
Acceleration
D . I . Medvedev
The Effect of a Prolonged Hypokinesia on the Human Blood
Circulation
A. L. Myasnikov, R. M. Akhrem-Akhremovich, L. I. Kakurin,
Yu. T. Pushkar ' , N. M. Mukharlyamov, V. S. Georgiyevskiy,
Yu. N. Tokarev, Yu. A. Senkevich, B. S. Katkovskiy,
A. N. Kalinina, M. A. Cherepakhin, V. A. Chichkin,
V. K. Filosofov and P. G. Shamrov
Some Problems of Professional Selection
V. D. Nebylitsyn and B. M. Teplov
The Sanitary Aspect of the Working Conditions Around
Ultrahigh Frequency Generators
M. I. Netreba
The Role of the Sinocarotid Reflexogenic Zone in the
Reaction of the Blood System to Reduced Barometric
Pressure
Yu. V. Nikolayenkov
Evaluating Some of the Organism's Reflex Reactions to
Breathing under Increased Intrapulmonary Pressure
P. V. Oblapenko
Studying the Nyctohemeral Rhythm of Functions in Conditions
of Limited Mobility
N . Ye . Panf erova
The Achievements and Goals of Space Medicine
V. V. Par in
Some Structural Principles of Flight Control and
Navigation Systems
Yu. A. Petrov
Page
309
312
316
3I8
321
32U
328
330
333
333
XI
Page
Pathomorphological Changes Induced in Animals by Rotating
Them Around Axes Running Through the Pelvic- Cardiac -
Cephalic Region 336
V. G. Petrukhin
The Pathomorphology of Transverse Overloads 339
V. G. Petrukhin and M. M. Sokolova
Some Problems of the Human Personality in Aeronautics,
Aviation and Astronautics 3U2
K. K. Platonov
Evaluating the Effectiveness of the Experimental Methods
Used in the Psychological Selection of Aviation Cadets 3U7
B. L. Pokrovskiy, T. I. Zhukova and V. P. Zukhar '
Some Reasons for Errors Made by the Pilots in Instrument
Flying 3^9
V. A. Ponomarenko and A. G. Shishov
Some Methods of Improving the Perception of Parameters
Controlled by a Human Operator 352
V. A. Popov, A. M. Pikovskiy, Yu. V. Kiselev and
Yu. V. Krylov
The Reaction of the Organism to the Informational
Characteristic of a Stimulus 355
V. A. Popov and A. S. Khachatur 'yants
Electrocardiograms in Dogs during Exposure to Certain
Altitude Factors 358
V. L. Popkov and I. N. Chernyakov
Effect of Oxygen Starvation on Motion Sickness 362
N. A. Razsolov
The Importance of the Study of Types of Higher Nervous
Activity in Man in Selecting and Training Flight
Personnel 366
A. A. Rogov, T. T. Gorlanova, M. M. Kantorovich and
N. T. Kovaleva
Some Regular Patterns in the Effect of Acceleration on
the Organism 368
D. Ye. Rozenblyum
xi 1
^,
Page
The Nervous System's Role in the Organism's Reactions
to Accelerations 370
B. M. Savin
Electroencephalograph^ Examination of Flight Personnel
During Long Flights 372
L. V. Sadovnikova
Functional State of the Vestibular Analyzer during the
First Few Hours Following Irradiation with Different
Doses 373
A. V. Sevan 'kayev
Histochemical Examination of the Changes in the Distribution
of the Effect of Dehydrogenase Succinate, Carboanhydrase,
Alkaline and Acid Phospbomonoesterase, Adenosine Triphos-
phatase and Sulfhydryl Groups of Proteins in Inner Organs
in Acute State of Oxygen Starvation 37^
S. N. Sergeyev
Contemporary Problems in Aviation Physiology 379
N. P. Sergeyev, V. A. Sergeyev and F. P. Kosmolinskiy
The Role of Reduced Reactivity of the Organism in Resistance
to Extreme Influences (Acceleration, Radiation) 38^
N. N. Sirotinin
Some New Indexes of Hemodynamics, Obtained by Means of
the Mechanocardiographic Method 3^"
M. N. Syviritkin
Metabolic Changes under the Effect of Parachute Jumping 387
Yu. K. Syzrantsev, Yu. F. Udalov and N. A. Chelnokova
Vitamins in the Diet of Aviators and Astronauts 390
Yu. F. Udalov
Changes in Excitability and Lability of the Visual Analyzer
under Conditions of Prolonged Nonstop Flights in
Multipassenger Turboprop Planes 393
A. I. Ustinova
Some Metabolic Indexes in the Astronauts Yu. A. Gagarin,
G. S. Titov, A. G. Nikolayev and P. R. Popovich 395
T. A. Fedorova, L. T. Tutochkina, M. S. Uspenskaya
M. M. Skurikhina and Ye. A. Fedorov
Xlll
Page
Effect of Angular Rotation Velocities on the State of
Several Visual Functions 398
A. B. Flekkel 1
Reactivity of the Organism and. Methods of Increasing Its
Resistance to Certain Flight Factors 401
I. M. Khazen
Histophysiological Changes in Animals Exposed to Accelerations 406
I. M. Khazen, E. M. Kogan and A. S. Barer
Some Results of Manned Space Flight and Problems in Space
Biology and Medicine h-09
V. I. Yazdovskiy
The Effect of Adequate Stimulations of the Vestibular
Apparatus on the Electrical Potential of the Stomach 410
V. T. Khlebas and N. P. Kozhukhar '
The Status of Anti coagulating Mechanisms under Conditions
of Prolonged Hypokineses 41 4
Ye. I. Chazov and V. G. Ananchenko
The Efficacy of the Pharmacological Preparation Nil in
Combating Motion Sickness of Air Transport Passengers 41 6
A. V. Chapek
The Influence of Age-Associated Changes in Older Pilots
during Re-Learning in the New Aviation Technology and
during Performance 419
A. V. Chapek, V. P. Yerokhin and I. P. Poleshchuk
Some Microorganisms as Indicators of Solar Activity and
Precursors of Solar Flares 422
A. L. Chizhevskiy
Significance of Parasympathetic Nervous System Tone in
Increasing Resistance to Flight Factors 424
M. D. Chirkin
Effect of Brief Physical Training on the Survival of White
Rats Kept under Conditions of Prolonged Hypodynamia and
Isolation 427
V. A. Shkurdoda
xiv
Page
Effect of Parachute Jumps on the Adaptive Reactions in
Persons of Different Age Groups it-29
S. N. Shurgin and A. N. Mazin
Physiological Reactions in Weightlessness U3I
Ye . M . Yugano v
Effect of Airplane Noise on Man and Noise Control Measures it-3^
Ye. M. Yuganov, I. Ya. Borshchevskiy, Yu. V. Krylov and
V. S. Kuznetsov
Effectiveness of Certain Methods of Selecting Personnel "by
Vestibular Tests h.37
Ye. M. Yuganov, S. S. Markaryan, I. I. Bryanov,
I. A. Sidel'nikov and R. A. Vartbaronov
Sensorimotor Coordination in Extended Weightlessness in
Actual Space Flight U39
V. I. Yazdovskiy, I. I. Bryanov, L. I. Kakurin, Yu. V. Krylov
and M. A. Cherepakhin
Radiation Reactions and Chemical Protection of Animals
Exposed to High-Energy Protons kk-2
S. P. Yarmonenko, E. B. Kurlyandskaya, G. A. Avrunina,
Ye. S. Gaydova, R. D. Govorun, R. L. Orlyanskaya,
G. F. Palyga, V. L. Ponomareva, V. I. Fedorova and
N . L . Shmakova
xv
FOREWORD
The conference on aviation and space medicine, the proceedings of
which are published in this collection, was held at a time of remarkable
achievements by our people in their striving for the peaceful conquest
of outer space. The realization of the first space flights of man testi-
fies to the magnificent accomplishments of Soviet science and engineering.
Soviet medicine has made a significant contribution to the prepara-
tion for and successful achievement of space flights. We are referring
here to space medicine, a new branch of knowledge that has evolved in
recent years from aviation medicine.
The last 30 years were marked by the blossoming of Soviet aviation
medicine. As long ago as 193*4-- -at an All-Union Conference on the Strato-
sphere, called at the initiative of the USSR Academy of Sciences- -the
leading scientists of our country were focusing on the medical aspects
of man's mastery of the stratosphere.
A conference on aviation medicine held in 1939 in Leningrad summed
up the results of the research done at that time and outlined future
research. It is now clear that the scientists of that era obtained
factual data and advanced theories which significantly affected the
safety of flights beyond the earth's atmosphere.
During the 25 years that have elapsed since the Leningrad conference
our scientists have done a tremendous amount of work to ensure the safety
of flights by civilian and military aircraft and made outstanding progress
in space medicine.
During the arduous years of World War II, Soviet aviation medicine
not only coped with current practical problems, but was able to ensure
the safety of the first flight of man in a rocket-propelled vehicle.
This was made possible by the extensive investigations conducted by many
teams in academic and other institutions on the effect on the human or-
ganism of the environmental factors characteristic of flight. These in-
vestigations were conducted as part of comprehensive high-altitude expe-
ditions, on special testing equipment simulating various flight factors,
and during flights themselves.
We remember the now deceased leaders of these scientific teams- -the
remarkable scientists L. A. Orbeli, V. V. Strel'tsov, I. P. Razenkov, G.
Ye. Vladimirov, L. N. Fedorov, A. P. Apollonov, V. G. Mirolyubov and
I. M. Dobrotvorskiy, whose efforts made possible the successful develop-
ment of aviation medicine and, later, space medicine in our country.
Whereas the subject matter of the 1939 conference dealt mainly with
the problems involved in ensuring the safety of high-altitude and pro-
longed flights, a distinguishing feature of this past conference was the
broad range of problems pertaining to man's survival on various vehicles
traveling in the earth's atmosphere and beyond--in outer space.
This conference was called because the matters discussed at the
meetings and conferences systematically organized by the Division of
Biological Sciences, USSR Academy of Sciences, showed that the time had
come for a detailed discussion of the accumulated data, if we were to
attract even more scientists into the fields of aviation and space
medicine.
This conference heard reports on increasing resistance to various
flight factors, with emphasis on those factors specific to space flight.
It examined the effect of gravity, which includes matters relating to
man's exposure to weightlessness and the influence of accelerations of
different intensities and directions. It dealt with the problem of liv-
ing under the conditions of extended flights on spacecraft. The conference
paid considerable attention to various medical aspects of space flight,
especially the main problems of flight physiology and psychology.
The papers fell into the following groups :
(a) Those dealing with the effect on the organism of various en-
vironmental factors (high barometric pressure, low partial pressure of
oxygen in inhaled air, high and low temperature, different kinds of
radiation, etc.).
(b) Those dealing with the effect on the organism of dynamic flight
factors (acceleration, weightlessness, noise, and vibration).
(c) Those dealing with physiology and psychology, hygiene of flight
activity, and problems involved in medical examination.
Acquainting large groups of physicians, biologists, and specialists
in other disciplines with the proceedings of the conference will con-
tribute to the further progress of aviation and space medicine in our
country .
V. V. Parin
RESULTS OF PHYSIOLOGICAL INVESTIGATIONS ON THE SPACESHIPS
VOSTOK 3 AND VOSTOK h
I. T. Akulinichev, R. M. Bayevskiy, V. Ye. Belay, P. V. Vasil 'yev,
0. G. Gazenko, L. I. Kakurin, A. R. Kotovskaya , D. G. Maksimov,
B. P. Mikhaylovskiy, and V. I. Yazdovskiy
One of the important objectives of the first tandem space flight of
the Vostoks was to investigate the effect on the human organism of pro-
longed weightlessness. Thanks to the use of several new techniques and
improved older ones employed during the preceding flights, it was pos-
sible to obtain a large amount of physiological information. Evaluation
of this information required that it be compared with the data derived
from ground tests simulating some of the conditions obtaining during
space flight and with the results of some laboratory investigations.
Extensive material (obtained by telemetry, from radio conversations,
logs kept on board, postf light reports and talks) was used to judge the
functional state of the astronaut's central nervous system during the
flight. Analysis of the material showed that prolonged weightlessness
had no appreciable effect on the functional capabilities of the central
nervous system of either astronaut. Their efficiency remained at a high
level; they performed a variety of tasks during the flight, some in-
volving flight duties, others for research purposes. The astronauts said
they did all kinds of work easily and without fatigue during the three
and four days of flight. This was objectively confirmed by psychological
tests administered during flight. According to EEG data, during the first
few hours of exposure to weightlessness there was a predominance of rhythms
with a frequency of 5-7 oscillations per second and a comparatively high
amplitude. Similar EEG changes have been noted in athletes after intense
physical exertion (L. I. II ' ina and S. V. Kukolevskaya, 1962). Later
there was a gradual shift toward high-frequency oscillations (p rhythm)
with a decrease in the average amplitude of the EEG biopotentials .
Worth noting are the dynamics of electric resistance of the skin,
which decreased during the first hours of flight and before landing, in-
dicating marked emotional stress on the part of the astronauts. The
daily periodicity of electric resistance of the skin- -increase at night
and decrease during the day- -remained unimpaired throughout the flight.
This fact tends to reflect the functional stability of the higher auto-
nomic centers.
Electro-oculograms (EOG) were recorded during flight to evaluate
the condition of the vestibular apparatus. Vestibular tests, sometimes
with simultaneous recording of an EOG, were included in the program to
determine any impairment of vestibular function. According to EOG data,
asymmetry of oculomotor reactions, which might indicate impairment of
the vestibular centers, and nystagmus were not detected in either astro-
naut. Analysis of the vestibular tests not accompanying the EOG record-
ing likewise failed to reveal any significant impairment of vestibular
function.
EOG investigations, besides the light they throw onjthe state of
the vestibular centers, are of definite value in appraising the level
of oculomotor activity, which to some extent may reflect the general
activity and motor activity of the astronaut throughout the flight .
The changes in oculomotor activity in both astronauts were phasic in
character. At the beginning of the flight it was high in A. G. Nikolayev,
less so in P. R. Popovich--l4— 6 eye movements per second.
Eye movements were sweeping and frequently uncoordinated. Motor
activity diminished during the 6th and 7th orbits and now solitary, now
group oscillations were recorded on the EOG. Subsequently, the EOG re-
vealed a periodic increase or decrease in oculomotor activity. At the
end of the flight, both astronauts had secondary, persistent intensified
oculomotor reactions, but this activity was much less than at the be-
ginning of the flight.
Cardiac activity was investigated by recording EKGs in the thoracic
lead. There was a slight pulse acceleration just before the launching
(Nikolayev- -from 98 beats/min to 112 beats/min; Popovich--from 9^ beats/
min to I36 beats/min), with a corresponding shortening of the PQ and QT
intervals). EKG changes during the active part of the flight were simi-
lar to the data obtained in the course of investigations in the centri-
fuge. The maximum pulse rate in the first minute of flight was 1 36
beats/min and I32 beats/min in Nikolayev and Popovich, respectively.
After going into orbit, the pulse rate dropped to the level observed U
hours before the launching during the 6th-7th orbits in Nikolayev and
during the 3rd-4th orbits in Popovich. It will be noted that in the
course of training in the centrifuge, the pulse rate returned to normal
in 5-IO minutes. No EKG changes were noted that might indicate impair-
ment of automatism, excitability, or conductivity. However, 3 single
extrasystoles were recorded in Popovich during flight; these also oc-
curred in the course of various tests and training. The nature of the
daily periodicity of cardiac activity did not change during flight .
According to pneumographic data, there were no respiratory abnor-
malities. During the active part of the flight there was some accel-
eration of respiration, which matched the data obtained during tests in
the centrifuge.
Thus, no pathological changes were noted in the physiological func-
tions of either astronaut throughout the flight.
In the active part of the flight there were functional changes that
matched the data obtained during tests in the centrifuge. The first few
hours of orbital flight were marked by some changes in the functional
state of various systems, as shown by a slow return to normal of the
pulse, nature of the EEG changes, and electric resistance of the skin.
The nature of the EEG changed in the course of prolonged ( 3-I4- days)
exposure to weightlessness, as shown by changes in the relationship
between the processes of excitation and inhibition in the higher divi-
sions of the CNS. At the same time, the mental activity and neuro-
regulatory capabilities of the astronauts remained on a high level.
CHANGES IN SOME INDICES OF RESPIRATORY BIOMECHANICS IN SICK AND
HEALTHY PERSONS UNDER THE CONDITIONS OF HYPOXIA
V. N. Alifanov
Respiratory biomechanics is a new branch of the physiology of res-
piration. It is pertinent to the clinical physiology (functional diag-
nosis) of respiration (B. Ye. Votchal et al., 19^9-1959; J. Comroe et
al., 1950, 1951; Brille and Hatsfeld, 196l; others). Respiratory bio-
mechanics has not been studied, so far as we know, under the conditions
of rarefied atmosphere and hypoxia.
This report presents data on changes in maximum pulmonary ventila-
tion (MPV) and respiratory reserve, volumetric flow rate of air upon
forced inhalation and exhalation (pneumotachometry), forced vital capa-
city of the lungs (FVCL), and forced vital capacity during the first
second of exhalation (Tiffno's index) while the subjects were in a
pressure chamber at an "altitude" of 5000 m and while breathing mix-
tures of gases containing 11 percent oxygen under the conditions of
normal atmospheric pressure. All data were obtained by means of a
spirograph and spirometabolograph. The subjects were 3O-W) year old
pilots, both healthy men and those with incipient signs of cardiovas-
cular disease (usually the initial symptoms of hypertension and car-
diosclerosis) or with residual symptoms of respiratory diseases (pul-
monary tuberculosis, lesions of the air passages, pneumothorax). We
examined a total of 75 healthy persons, 30 persons with cardiovascular
disease, and 30 persons with respiratory disease. Changes possessing
a reliability of at least 95 percent are considered regular.
MPV--an index both of respiratory function and of systemic condi-
tion—is distinctly reduced by several pathological conditions (N. A.
Troitskiy, 19^9; M. M. Tushinskaya, 19^9; A. G. Dembo, 1957; others).
It is evident from the table that at an "altitude" of 5000 m all the
subjects exhibited a significant increase in the MPV averaging 20-28
percent. No significant changes in the MPV were noted on breathing a
hypoxic mixture. In the healthy persons, the increase in the MPV in
rarefied atmosphere was at the expense of a deepening of respiration,
but in those with impaired health this increase was related mainly to an
acceleration of respiration, indicating that these persons had a less
perfect mechanism of adaptation reactions. It is interesting to note
that an increase in the MPV occurred at an "altitude" of 5000 m even
when oxygen was breathed. Aerodynamic calculations show that in rare-
fied air, resistance of the respiratory passages drops in proportion to
the density of inhaled air. We believe that the increase in the MPV
in rarefied air is due mainly to a lowering of resistance to breathing.
The so-called respiratory reserve, to which some authors attached
considerable significance (M. M. Tushinskaya, I9U9), is closely related
to the MPV. However, the respiratory reserve changed in uncharacteristic
fashion in our investigations.
In recent years many authors have been concentrating on the deter-
mination of the forced vital capacity of the lungs (FVCL), especially
by seconds (Tiffno et al., 19*4-9; Comroe etal., 195^; G. 0. Badalyan,
I96I; others). The table shows that the FVCL did not change signifi-
cantly in our investigations. Tiffno 's index in rarefied air had a
distinct tendency to be low in the healthy persons and in those with
residual symptoms of lung pathology. Changes on breathing the hypoxic
mixture were not characteristic, showing that with good tolerance of
moderate hypoxia there is no pronounced impairment of respiratory bio-
mechanics. The tendency for Tiff no's index to drop at an "altitude" of
5000 m is to be attributed to the aerodynamic properties of less dense
air rather than to physiological mechanisms.
Pneumotachometry (B. Ye. Votchal's method) is of value in judging
respiratory function. It is evident from the table that the space
velocity of forced inhalation and exhalation on breathing the hypoxic
mixture did not change significantly in our subjects, although it was
somewhat low in all cases. At an "altitude" of 5000 m the space velocity
of inhalation and exhalation regularly increased in all the subjects
(the values are presented in the table with an allowance made for the
difference in barometric pressure). We believe that a moderate decrease
in the space velocity of forced inhalation and exhalation is typical of
hypoxic conditions and that an increase in this velocity in rarefied air
is probably due to a lowering of resistance to respiration.
The findings described above not only broaden our knowledge of the
effects of rarefied atmosphere on respiration, but have important functional
ps of
jects
Functional
indices
Examination
conditions
Mean value + error of mean
or difference
Reliability in %
O 3
U to
<3
5000 m
Hypoxic
mixture
5000 m
Mixture
+>
H
cd
<u
K
MPV (in liters)
FVCL (in liters)
Tiff no's index
(in liters)
Forced inhalation
(in liters/sec)
Forced exhalation
(in liters/sec)
Initial hypoxia
Initial hypoxia
Initial hypoxia
Initial hypoxia
Initial hypoxia
79.0 + 3.2
97.0 + 1jj..8
3-° + 0.13
3-0 -
2-5 + o.i6
2.1 -
5.7 + 0.17
6.5 + 0.16
5.2 + 0.16
6.1 + 0.19
66.7
2-5 + 0.07
2.7 "
2-3 + 0.19
2.2 "
5-3 + 0.17
5-2 "
5- h + 0.17
5-1 "
More than
95
9^
More than
95
More than
98
Less than
50
95
Less than
90
1+0
80
05
O
to
gj <U
F> to
O ctj
•H CD
nd to
in -H
oJ -cJ
o
rCl
+>
•H
is
MPV (in liters)
FVCL (in liters)
Tiffno's index
(in liters)
Forced inhalation
(in liters/sec)
Forced exhalation
(in liters/sec)
Initial hypoxia
Initial hypoxia
Initial hypoxia
Initial hypoxia
Initial hypoxia
60.5 ± 5-2
81.5 + 6.2
2-^ + 0.2
2-3 '
1:1 ± °' 06
5-1 + 0.2
5-7 ± 0.2
k.9 ± 0.2k
5.3 + 0.2
6K.2 + 5-9
76.8 " J *
3- 1 + 0.2
3-3 '
2, 3 + 0.3
2.7 "
11 * °-T
More than
95
50
More than
99
More than
95
90
50
80
20
More than
95
-J
ch to
O -P
o
to d)
Functional
indices
Examination
conditions
Mean value + error of mean
or difference
Reliability in $
3 ,Q
O 3
*H to
o
5000 m
Hypoxic
mixture
5000 m
Mixture
MPV (in liters)
Initial hypoxia
58.0 + 0.6
57.0 + 1<9
57-2 "
More than
20
78.8 + 11 A
95
!>3
O
FVCL (in liters)
Initial hypoxia
2 -5 + 0.21+
2 -7 + 0.11+
Less than
80
-P
U CO
■H Ctf
2.1 '
2.9 "
90
ft <u
CO CO
Tiffno's index
(in liters)
Initial hypoxia
?'! + 0.06
1. ( "
2- 1 + o. 3
2.3 - 3
More than
99
50
,3
-p
Forced inhalation
Initial hypoxia
5-6 + 0.3
^•7 + 0.2
99
60
>
(in liters/sec)
6.5 + 0.15
U.5 "
Forced exhalation
(in liters/sec)
Initial hypoxia
5-3 + °-3
5-9 + 0.2
£'.25* °- 7
98
Less than
90
CO
Hfe
diagnostic value. Medical investigation of respiratory mechanics in
persons subjected to the commonest functional load in aviation, i.e.,
pressure -chamber "elevations" to 5000 m > is undesirable because it is
useless in detecting incipient impairment of this form of respiration
and it may even confuse the physician. We therefore make the highly
important and, to our way of thinking, practical conclusion that res-
piratory biomechanics should be investigated under the conditions of a
hypoxic load only when the inhaled air (gas) possesses ordinary density.
CHANGES IN BIOELECTRIC ACTIVITY OF THE MYOCARDIUM IN MAN
AFTER EXPOSURE TO HYPOXIC HYPOXIA ACCORDING TO THE
DATA OF VECTOR ANALYSIS
V. N. Alifanov and L. M. Zemesheva
There are few references in the literature to vector analysis of
EKGs recorded under the conditions of hypoxia (Tittle, 19^0, Gurtler et
al., 195^; V. N. Alifanov, i960 and 1961). These reports contain data
on frontal vector measurement. We are unaware of anything dealing with
sagittal vector measurement under similar conditions.
Our investigations were conducted in a pressure chamber where the
subjects remained for 30 minutes at an "altitude" of 5000 m. EKGs--
taken before the "climb" and after 20 minutes at the "altitude "--were
recorded in standard, amplified, and unipolar thoracic leads, which
made frontal vector measurement possible, and in Aricci's leads, which,
according to Zuckerman (1961), permit vector analysis of the EKG to be
made in a sagittal plane. Pilots 35-^5 years of age with good tolerance
of hypoxia were the subjects. This report presents the results of ex-
aminations of 15 healthy persons and 15 persons with incipient athero-
sclerotic cardiosclerosis. All the data were statistically processed
for reliability. The results with a reliability of at least 95 percent
are considered regular. The figures are presented in the table below.
It is evident from the table that in the healthy persons the most
characteristic changes occurred in connection with frontal vector meas-
urement. With hypoxia there was a regular turn of the ventricular vector
of AQRS depolarization to the left (averaging 30°), some tendency for the
AQRS to decrease (averaging U-5 M^vs), regular increase in the spatial
divergence of the AQRS and AT vectors (R/T ratio), and a tendency for
the divergence of the vectors of ventricular and atrial excitation (the
R/p ratio proposed by V. N. Alifanov, i960) to increase. The other ratios
of frontal vector measurement changed less reliably in the healthy persons.
10
Average Data of the Direction and
Magnitude of Cardiac
03
O
<D
Biopotential Vectors in the Frontal
and Sagittal Planes
-p
o
tt)
•1-3
Conditions
Direction
vectors :
degree.
of
Ln
Magnitude of
vectors in uvs
Ratio
in
degrees
Ph
AP AQRS AT
G
AP AQRS AT G
R/p
r/t
iH
Initial
50 51 37
35
7-9 29.8 23.6 49.7
21
29
03
-P
Hypoxia
55 21 33
33
7.1 25.3 23.8 U9.5
38
ho
O
Reliability of differ-
+3
P-4
ence in percentage
- 98 -
-
90 -
90
99
H
03
(1)
Initial
50 28 65
UU
9.7 21.9 24.5 36.6
28
hB
K
•P
-P
•H
M
Hypoxia
Reliability of differ-
55 28 66
^3
11 22.8 23.9 ^0.9
36
56
03
CO
ence in percentage
90 - -
-
- - - -
90
98
H
Initial
51 11 29
18
7.6 28.7 25.7 U8.9
ko
36
to
■H
-p
Hypoxia
53 h 27
18
6 23.2 22.0 38.8
k6
35
O
o
Reliability of differ-
h
h
ence in percentage
- 98 -
-
98 95 90 95
90
-
o
w
O
r-H
03
Initial
52 -h 57
28
8.3 21.8 18.7 3I.2
55
72
■H
-P
-P
Hypoxia
^6 3 51
27
9 22.1 16 32.6
50
67
03
•H
to
Reliability of differ-
o
CD
ence in percentage
90 - -
-
- - - -
—
90
Note: No mention is made of reliability less than 90 percent; the
positive direction of the vectors is indicated without a +
sign in front of the degrees of direction.
The following points must be emphasized. In healthy persons exposed
to hypoxia, changes in the spatial direction of the frontal vectors were
dominant. At an "altitude" of 5000 m the direction of the vector of re-
polarization of the AT and so-called "ventricular gradient" G changed
little in conformity with the AQRS. The atrial AP vector deviated fre-
quently, but moderately, to the right. Changes in the ratios of sagittal
vector measurement at an "altitude" of 5000 m were less pronounced in
the healthy subjects.
It is evident from the table that neither the direction nor the mag-
nitude of the sagittal vectors changed reliably under the conditions of
hypoxia. There was a distinct tendency for the AP vector to assume a more
vertical position with a slight increase in length. The R/T and R/p ratios
changed in the sagittal plane just as in the frontal plane.
11
As for the physiological mechanisms underlying these changes, anal-
ysis of all the EKG leads and some hemodynamic characteristics (arterial
pressure, systolic volume of the blood, etc.) reveals that, in hypoxia
the deviation to the left of the main vector of excitation of the ven-
tricular musculature of AQRS was caused chiefly by intensification of
the functional load on the "left heart" and, in part, by the shifting
of the heart to the left when the diaphragm stood somewhat higher at
the "altitude" of 5000 m.
V. N. Alifanov (i960) noted that pronounced hypoxia gives rise to
symptoms of reflex overloading of the "right heart" owing to increased
pressure in the pulmonary artery system. This overloading was initially
manifested in a deviation to the right and increase in the AP vector.
A reflex load on the "right heart" probably occurs to some extent in all
cases of hypoxia, this was reflected in our investigations in the ver-
ticality of AP, especially marked in the sagittal plane.
Similar investigations in persons with incipient cardiosclerosis
are of great interest because this disease is common and because there
are few references in the literature to the effect of hypoxia on persons
with various physical disorders.
It is evident from the table that frontal vector measurement in
persons with cardiosclerosis has its own peculiarities. At an "altitude"
of 5000 m the direction of the vectors was, in general, the same as in
healthy persons, except for a regular decrease in the value of all the
vectors . The decrease in magnitude of the myocardial biopotentials in
these subjects after exposure to hypoxia was so pronounced that it
masked the value of the spatial displacements of the vectors . Moreover,
the nature of the changes in the sagittal vectors in these subjects
differed somewhat from that in the healthy persons . There was a slight
tendency for the AP vector to deviate forward and to a more vertical
projection of the AQRS.
It is reasonable to assume that persons with incipient cardiosclero-
sis who are fairly tolerant of hypoxia generally have the same physio-
logical mechanism of changes in heart potentials as that described for
healthy persons, but with indications of some oxygen deficit of the myo-
cardium, reflected in a regular decrease in the magnitude of the frontal
vectors. This may appear on the EKG in the form of some general decrease
in the voltage of the P, R, and T waves . But this decrease is so mod-
erate that it is not detected, as a rule, in the course of an ordinary
analysis of the EKG. Only a quantitative vector analysis of the EKG can
reveal this phenomenon, which is important for functional diagnosis.
12
BIOTELEMETRY ON" MANNED SPACE FLIGHTS
G. V. Altukhov
Medical monitoring of manned space flights differs from ground ob-
servation methods in a number of respects : lack of personal contact be-
tween the physician and astronaut, limited amount of medical information
transmitted from the spaceship, and impossibility of rendering effective
aid in case a serious health problem should arise.
Various radiotelemetry systems are currently used to transmit medi-
cal and biological information from a spaceship. Unlike laboratory
equipment, the instruments on a spaceship must be very small and light,
and operate efficiently and reliably when exposed to overloads and other
flight factors . Such apparatus was used for the first time on the Novem-
ber 3, 1957 flight of the sputnik carrying the dog Layka and it recorded
several physiological functions of the animal. The experience gained in
the flights with animals enabled Soviet scientists to design special
radiotelemetry, radiotelephonic, and television devices to provide medi-
cal monitoring of the astronauts Yu. A. Gagarin and G. S. Titov on the
Vostok and Vostok 2.
Furthermore, the flights of animals resulted in the gathering of
experience on interpretation, mathematical processing, and analysis of
information received by ground radiotelemetry stations in the form of
oscillographic curves.
On Gagarin's flight, the program for telemetry of physiological
functions included recording of an electrocardiogram in two leads, a
pneumogram, and pulse rate. On Titov' s flight, the program was broadened
to include recording of a kinetocardiogram, which characterizes myocardial
contractility. The physiological methods used on these flights deal mainly
with the autonomic body functions.
On the tandem flight of A. G. Nikolayev and P. R. Popovich, the phys-
iological investigations were supplemented by recording of an electro-
encephalogram, electrooculograra, and cutaneogalvanic reaction, which
reflects the state of the central nervous system and vestibular apparatus.
Higher nervous activity and efficiency during various stages of the
flight were evaluated from the information obtained during radio conver-
sations, television, objective physical examination, and the astronauts'
oral report. Also, radiotelemetric recording of the principal hygienic
characteristics was carried out on ail four flights: barometric pressure,
oxygen and CO2 content, humidity, and air temperature in the cabin of the
spacecraft. During descent, the physiological functions of the astronaut
were recorded by an independent system.
HS$\.
13
Operational medical supervision was effected at ground receiving
stations by specially trained medical personnel who at each stage of the
flight analyzed the data obtained from radiotelemetry, radio conversa-
tions, and television and drew conclusions on the condition and effi-
ciency of the astronauts.
All medical and biological information was subjected to a thorough
scientific analysis after the flights.
Interpretation of telemetric curves differs in several respects
from the interpretation of oscillograms obtained in laboratory experi-
ments. The difficulties in interpreting the curves arise from all kinds
of interference which frequently masks useful information. The record-
ing of physiological parameters in the form of discrete curves likewise
greatly complicates the analysis. As a result, it was necessary to work
out special methods of interpretation. In-depth scientific analysis of
information obtained during flight also included mathematical processing
techniques, which serve to produce a maximum of useful information on
the physiological state of the organism during flight. This is of great
value owing to the uniqueness of these experiments. Accordingly, after
they were interpreted, all the data were grouped by flight stages (pre-
launching period, the craft's going into orbit, orbital flight, entry
into the dense layers of the atmosphere, descent, and landing).
One of the purposes of mathematical processing of the information
was to obtain generalized quantitative characteristics of the pertinent
physiological indices during different flight stages and to determine
the direction of changes in these indices by finding an analytical re-
lationship between their averaged values and the time of the flight as
well as the interrelation between the dynamic series of the physiological
indices during different stages. The medical and biological information
was processed mathematically with the help of semiautomatic calculating
machines and electronic computers.
Flight experiment data cannot, of course, be analyzed scientifically
without comparing them with the results of the preflight training and
laboratory tests of the astronauts. This approach makes it possible to
use information theory for predicting the state of physiological func-
tions during space flight .
The volume of information will grow as the flights become longer.
This makes it urgently necessary to utilize the achievements of radio-
electronics and computer technology to automate maximally the process
of interpreting recordings of physiological parameters and entering
them into computers for subsequent analysis based on statistical prob-
ability methods .
As the flights increase in duration and distance, the scope of phys-
iological investigations will broaden, resulting in an increase in the
Ik
total amount of information transmitted by radiotelemetry channels.
Even now it is necessary to use computers for automated medical super-
vision directly on the flights, and they make it possible to transmit
the maximum amount of information over telemetry channels of limited
capacity. Such systems ought to carry out prolonged and continuous medi-
cal monitoring in accordance with a specific program, and generalized
physiological and hygienic information right on board the craft, thus
permitting the telemetry channels to become unloaded and the medical
monitoring system more noiseproof. Solution of the medical problem
must take cognizance of the fact that all the values of the physiological
and hygienic parameters to be recorded are of three kinds : one reflects
the normal values for each individual; the other two characterize the
values that are above and below normal.
Owing to the relative simplicity of the logical operations that
determine the algorithm for the medical monitoring problem, the latter
can be solved by miniature logical circuits of simple design executed
on semiconductor elements. There are now available experimental labora-
tory models of a monitoring device that make it possible to analyze and
generalize the information of three physiological parameters--pulse,
respiration rate, and body temperature- -on the spaceship itself. The
device is of value in recording the condition of the astronaut in rela-
tion to a combination of input parameters and in accordance with the
algorithm controlling its operation.
The introduction of automatic medical monitoring systems function-
ing on the principle of combining deviations in the parameters to be
monitored is making it necessary to devise a scientifically sound coding
program and to choose the physiological parameters correctly.
SOME PROBLEMS IN THE PSYCHOLOGY OF FLIGHT ACTIVITIES
B. S. Alyakrinskiy
The task of a modern airplane pilot is very complex, particularly
with respect to the perception of the numerous stimuli that serve as
signals for various actions on his part. The process of perception is
usually considered from the standpoint of organizing the pilot's atten-
tion. Experienced instructors have done much in developing a program
for focusing and shifting the pilot's attention during different portions
of a flight. In essence, the pilot is taught "where and how to look,
what to see, what to listen for, how to hold the control stick, what to
feel with the hands, legs, and body, and the best position to assume"
15
(A. F. Katayev) . Pilots are taught the art of navigation on the basis
of the vast practical experience of their instructors. Yet many prob-
lems are still unsolved and numerous accidents are due to shortcomings in
the training of young fliers. But this is not the fault of the practical
men. The reason is rather the inadequate theoretical foundation of flight
activities, specifically the psychology of reading the aviation instru-
ments that are now to be found in virtually every kind of airplane.
Instrument navigation is the most difficult part of flying. The
pilot must read many instruments that tell of flight conditions and
functioning of the engine (although he has more work than this); he
must interpret the readings to form an opinion as to the prevailing
situation, make a decision, and then act on it. Performance of all
these operations is greatly hampered by the lack of time; a complex
flight situation does not permit enough time to receive and digest the
instrument information and to make a correct decision. This results in
tension and a threat to the flight's conclusion. If the pilot had enough
time, he could analyze the situation carefully, having studied his in-
struments (along with, say, radio information), prepare an optimum plan
of action, and carry it out in full control. In reality, however, the
pilot does not have these opportunities. Since aviation is becoming
increasingly swift, the realistic approach to optimization of flight
activities lies in the direction not of increasing the time available
to the pilot for flying the airplane, but of accelerating the operations
involved through better organization. The pilot's work must be so or-
ganized that all his actions are as quick and efficient as possible.
In devising a plan for piloting an airplane based on this principle,
let us imagine that it is to be accomplished by some "ideal control de-
vice", the nature of which is of no concern to us. Let us view each in-
strument as an independent channel of information and a single collection
of information from any channel as a unit of information, assuming that
each glance at the instrument constitutes such a unit. The "idealness"
of the control device lies in the fact that it can receive all the in-
formation needed, interpret it, develop an appropriate plan of action,
and carry out this plan to satisfy the requirements of a changing situa-
tion. In other words, the "ideal control device" never suffers from in-
sufficient time, for it can operate at any rate of speed. With such a
device we could guarantee the safety and efficiency of flight on any
airplane if we were able to prepare for it the best plan of action in
any conceivable situation.
Let us imagine the movement of an airplane controlled by our "ideal"
pilot at some portion of the flight route marked by a rapidly developing
situation. Let the plane travel through this portion in a minute. Let
us break down this time into segments of any duration (say 5-second in-
tervals), and take these intervals for units of time and plot them on the
abscissa of a rectangular system of coordinates (on the time axis).
16
Within each unit of time let us determine the modality (category) of the
information and the number of units of each modality in accordance with
our plan of optimizing the pilot's tasks at given stages of the flight.
In other words, let us answer the questions of how many times and
what instruments the pilot is to glance at during each succeeding unit
of time (taking into consideration the fact that information is received
and processed at the same time). These data are plotted on the ordinate
(information axis). If we now join in an unbroken line the apexes of
the segments reflecting the number of units of instrument information of
different modality, we will obtain a curve characterizing the optimum
operating conditions of an "ideal" pilot during a given portion of the
flight, although, to be sure, only with respect to the load on its visual
analyzer and only as far as the receiving of instrument information is
concerned. The resulting curve can be called an "objective informogram"
or informogram characterizing the optimum cross section of pilot activity
during a given portion of a flight. Such an objective informogram can
be calculated by experienced pilots, navigators, and engineers together.
We must emphasize once again that an objective informogram reflects only
the process of collecting instrument information in such a volume and in
such a sequence as to ensure safety and efficiency at a particular stage
of a flight. Moreover, this process is not restricted in any way, i.e.,
it can take place at any speed and with whatever accuracy may be required.
This hypothetical, unrestricted rate of collecting instrument infor-
mation is simply a method of determining the actual, objectively existing
demands made on the "device" that controls an airplane in some specific
way (the operation of the optic apparatus of this device in receiving
instrument information). In constructing an objective informogram, one
must realize that it might be impossible even for the best of pilots to
follow it. Nevertheless, the informogram shows what is required of a
person who pilots an airplane from instruments in order to optimize his
activity. This is true, however, only when we know the actual, capabili-
ties of very able pilots. In other words, an objective informogram will
be genuinely valuable only when it is supplemented by an informogram that
reflects actual human capabilities in receiving and processing information
under specific flight conditions on a specific airplane. Since psycholo-
gists know the maximum speeds at which instruments can be read intelli-
gently, it should be possible to construct an informogram in accordance
with the above-described principle that will be generally accessible to
human beings. Such an informogram may be called "subjective". It will
be accessible to some abstract pilot who possesses all the positive
mental qualities that are known to science and are essential for re-
ceiving and processing instrument information. The construction of a
subjective informogram can be considerably facilitated by relevant ex-
periments. The use of practical experience is obligatory.
To construct a subjective informogram is to solve one particular
problem involved in working out the algorithm of an airplane pilot. The
17
problem of constructing a subjective informogram has been largely solved
in practice, at least as far as the qualitative aspects are concerned.
There are available compulsory schemes for apportioning the time of the
pilot and directing his attention to the instrument panel. However, the
time characteristics of this process are barely indicated. It is the
primary purpose of both the objectively prescribed and the subjectively
accessible informograms to outline the specific tasks of the pilot with
respect to the time they have to be performed.
A comparison of the objective and subjective informograms will make
it possible to analyze in detail specific flight conditions (of course,
only in the aspect under consideration) and judge the relationship be-
tween the demands made on man by flight activities, particularly the
functioning of his visual analyzer. In making such a comparison, our
attention will be first drawn to those portions of the flight within
which the informogram curves will diverge the most. This will enable
us to detect the weak points in the pilot's sensory activity and thus
properly choose from the requisite number of information units prescribed
objectively the number of units that are subjectively accessible to re-
ception on the basis of their relative importance. Subjective and ob-
jective informograms will help designers of aviation instruments to create
instruments that reflect man's true capabilities.
In devising individual training programs, it is also possible to
have a "characteristically individual informogram, " which, when compared
with the subjective informogram, would enable one to predict the diffi-
culties involved in relearning and, in part, learning the science of
aerial navigation. Construction of the aforementioned informograms
should lead to the construction of corresponding actograms reflecting
the qualitative and quantitative (primarily on the time axis) aspects of
the motor activity of a modern airplane pilot. All this work constitutes,
on the whole, a practical method of analyzing flight activities in depth,
thus greatly facilitating the task of gaining insight into their intimate
mechanisms. There is scarcely any need to mention the close connection
between the views set forth in this report and the problem of flying
capabilities.
Investigation of the psychology of flight activities should be com-
bined with an elucidation and detailed description of the links in the
"pilot-airplane" system, links which should rightly be called "vitally
necessary" in contrast to the "resultantly necessary" links that are very
commonly encountered in the "man-machine" system.
18
SOME PROBLEMS IN ENSURING THE RADIATION SAFETY OF SPACE FLIGHTS
V. V. Antipov, V. G. Vysotskiy, B. I. Davydov, N. N. Dobrov,
V. S. Morozov, G. F. Murin, M. D. Nikitin, and P. P. Saksonov
Biological experiments on various spacecraft, astrophysical investi-
gations, and, finally, the flights of Soviet and American astronauts
have convincingly shown that brief orbital flights below the earth's
radiation belts and in the absence of intense solar activity are safe
as far as radiation is concerned. The radiation doses received by the
astronauts as a result of primary cosmic radiation and radiation of the
outer radiation belt were low and noninjurious to the human organism.
However, on longer flights involving the crossing of radiation belts
and especially if there are chromospheric bursts on the sun, ionizing
radiation would definitely be a threat to the health and lives of human
beings. With longer flights and orbital flights passing through the
radiation belts, cosmic radiation will obviously be the principal ob-
stacle to man's conquering of space.
Protons are the commonest form of penetrating radiation in outer
space. About 85 percent of them are in primary cosmic radiation. Large
quantities are generated during chromospheric bursts on the sun and they
form part of the earth's inner radiation belt. Yet there are no experi-
mental data on the characteristics of the biological effect of protons,
their RBE, as compared with X-rays and T-rays.
From some references in the literature (E. B. Kurlyandskaya et al.,
A. V. Lebedinskiy et al., and others) and the investigations of members
of our laboratory (V. S. Shashkov, B. L. Razgovorov, T. Ye. Burkovskaya,
and others) it is reasonable to assume that the RBE of protons with an
energy above 100 Mev constitutes a quantity somewhat less than 1 with
respect to the LD for rodents. However, these data were obtained by
using a variety of accelerators characterized by very high dose rates
and pulse radiation. This should be kept in mind when evaluating the
RBE of the protons of primary cosmic radiation, inner radiation belt,
and solar bursts .
It is believed that the RBE factor for a particles and nuclei of
the heavier high-energy elements ranges from 2-10. However, this as-
sumption is based only on theoretical calculations, since it is still
impossible to perform experiments on animals under laboratory condi-
tions owing to the lack of sufficiently powerful accelerators.
Another important problem, in which there are virtually no experi-
mental data available, is the combined effect of radiation and other
flight factors (vibration, acceleration, weightlessness, change in
19
composition of gases, etc.). Yet it is essential to know the specific
role played by cosmic radiation in the overall effect of the various
flight factors on the human organism and the influence of the nonradia-
tion flight factors on the qualitative and quantitative aspects of the
biological effect of radiation. Without this information it is impos-
sible to formulate scientific recommendations on the pharmacotherapy
and prevention of radiation injuries .
Our research (B. I. Davydov, V. G. Vysotskiy, T. S. L'vova, N. I.
Suprunehko, and others) indicates that acceleration and vibration will
variously affect the development of radiation lesions depending on
when and in what order these factors are applied. For example, 5-6
days after being irradiated, animals tolerate the effects of vibration
and acceleration more poorly than do nonirradiated animals. In addi-
tion, these two factors aggravate the course of radiation sickness.
On the other hand, if vibration or acceleration is used prior to ir-
radiation, they not only do not aggravate the radiation effect, they /
even tend to weaken it.
The absence of suitable experimental data on the KBE and combined
effect of flight factors plus radiation makes it impossible to make
scientifically sound recommendations on maximally permissible radiation
levels for astronauts .
Our recommended maximally permissible dose of cosmic radiation of
25 ber per flight is based on theoretical calculations and the known
experimental and clinical facts on the injurious effect of ionizing
radiation under terrestrial conditions. Such unconditional extrapolation
of the data to cosmic radiation is inadmissible. Therefore, the recom-
mended maximally permissible dose of 25 ber is to be regarded as provi-
sional. The dose will be changed in either direction as more experi-
mental data become available on the biological effect of the individual
components of cosmic radiation and on the effectiveness of protective
measures.
It is obvious that the ideal protection is physical, mechanical
protection, i.e., shielding of the cabins of the spacecraft with a thick
layer of lead or other material. However, calculations have shown that
this is impossible, at least for the present.
Chemical substances which are now available increase resistance to
radiation, but most of them for one reason or another cannot be used
under the conditions of space flight, as we shall show in more detail
in another report. The search for effective pharmacochemical and bio-
logical means of providing protection against cosmic radiation is es-
sential to ensure the safety of space flights. Many biological objects-
higher and lower plants, microorganisms, and other representatives .of
the animal and plant worlds--will accompany the astronauts in long flights
20
and provide food and oxygen, utilize carbon dioxide and other harmful
impurities.
The question naturally arises whether certain doses of cosmic radi-
ation can induce hereditary changes in these plants and animals that
might severely disrupt the balance existing in the closed ecological
system of a spaceship. From the scientific point of view, this possi-
bility cannot be ruled out. That is why it is essential for us to know
the effect of cosmic radiation and other flight factors and, if such
disruption can occur, find ways and means of preventing the radiation
from harming the crew and the various biological objects on board.
A solution of the problems outlined above will make it possible to
devise scientifically sound measures to ensure the radiation safety of
space flights . The main elements in such a system are :
(a) Reliable monitoring of the radiation level in the cabin of the
spacecraft by individual and biological dosimeters mounted in the cabin.
(b) Scientifically sound forecasting of the radiation situation in
space, especially chromospheric bursts on the sun.
(c) Effective antiradiation pharmacochemicals and biologicals.
There are of course, many unresolved problems, since space radio-
biology is still in its infancy. However, there is reason to hope that
radiation safety of space flights will be achieved through the combined
efforts of specialists in different fields.
EFFECT OF DIFFERENT PARTIAL PRESSURE OF OXYGEN AND ENVIRONMENTAL
TEMPERATURE ON REGULATION OF TEMPERATURE RELATIONS
IN THE ORGANISM
I. I. Antonov
A major problem in the study of bodily functions under the condi-
tions of an altered gas medium is the effect of different partial pres-
sures of oxygen and environmental temperature. A number of important
theoretical questions are still unanswered. Although of little practical
significance, perhaps, they nevertheless are highly interesting from the
broad general biological point of view. These include change in heat ex-
change in various organs and tissues and the mechanisms by which hypo-
and hyperoxemia influence the thermoregulatory function of the central
21
nervous system (CNS). A problem of considerable practical as well as
theoretical significance is the extent to which environmental tempera-
ture affects the balancing of heat exchange between the environment and
organism exposed to different partial pressures of oxygen. These two
matters are discussed in the present report.
The investigators of heat exchange fall into two main groups . One
group considers the principal reason why the experimental animals died
is that their bodies were chilled at low temperatures and that their
nervous systems (Kartshevskiy, 1908; Veselkin, I9U8; Antonov, 195^J
others) and metabolic processes (Smith, 1898; Hill and McCloud, 1903;
Shick, 19^8; others) became exhausted. The second group maintains the
opposite opinion (Gellhorn, 1937 J Campbell, 1938; Hirsch and Wagner,
19^5; Gubler, 1952; others).
Our data, obtained from two series of experiments (total of 200 )
on animals, showed that the temperature change in some viscera and pe-
ripheral tissues at an environmental temperature of 20° C and partial
pressure of are far from being the same. The change in brain tem-
perature is particularly noteworthy. In hypoxemia there was invariably
a complete distortion of the normal temperature relations between the
surface and deep layers of the brain after a general lowering of brain
temperature. With the development of oxygen deficiency, the ordinary
temperature difference between the surface and deep layers leveled out
or became temporarily reversed. We observed a similar distortion of
brain temperature relations following the toxic action of high pressures
of , especially in hyperoxemic convulsions.
In analyzing the data obtained from brain thermometry, we expected
to find an elevation in the deep layer as a result of excitation of the
motor and autonomic elements of the nervous system during convulsions.
However, the sharp drop in the subcortical region and rise in the cor-
tical led us to assume on the basis of Gramenitskiy ' s data (1950) (the
temperature of the deep layers is higher than that of the inflowing
blood and, conversely, the temperature of the surface layers is lower
than that of the inflowing blood, resulting in the emission of heat by
the brain) that in both hypo- and hyperoxemia heat is emitted in these
regions chiefly through the blood. We also took into account the fact
that hypoxemia is accompanied by reflex dilatation of the cerebral blood
vessels and intensification of the blood flow (Marshak, 19^0). Conse-
quently, the blood gives off its heat to the surface layer and obtains
it from the deep layer. Our assumption was confirmed by experiments
with constriction of the common carotid arteries.
The mechanism of action of high pressure of oxygen is somewhat
different. The investigations of Benke, Forbes, and Motly (1936),
Sorokin (19^9), and Lambert son (1953) showed that at first there is
22
constriction of the cerebral blood vessels and a slowing of the blood
flow and that it is only after oxygen poisoning that the vessels become
dilated. This phenomenon was clarified by the research of M. P. Brestkin
and his school who showed that under pressure blocks the enzyme sys-
tems, i.e., neuroreflex regulation is impaired just as in hypoxemia.
This similarity in mechanism of action of two such inherently dif-
ferent external influences as hypo- and hyperoxemia made it possible to
study simultaneously the impairment of temperature relations in the or-
ganism and to determine the common elements in their mechanism of action
on thermoregulation.
The study of other temperature data revealed a substantial and regu-
lar drop in rectal temperature starting at the moment of exposure and
progressing during the convulsions. It is caused by a lowering of the
level of metabolic processes in the organism and closely reflects the
true temperature of the blood under these conditions .
Considering the significant fluctuations in temperature of the skin,
subcutaneous tissues, and muscles after a general drop and the fact that
the organism regulates its heat balance with the environment chiefly
through the skin, it would seem that such fluctuations are caused by a
reflex adaptation response to these external stimuli. The fluctuations
in temperature of the muscles are of unusual interest. It rose during
the first convulsions probably as a result of increased heat production
in the "working" muscles but remained unchanged during the later con-
vulsions owing to constriction of the peripheral blood vessels and a
slowing of the blood flow. However, the temperature of the liver and
kidneys was less variable either because of the considerable heat pro-
duction of these organs or because of the constancy of their blood
supply.
The combination of different partial pressures of 0„ and low (-10°)
and high (U0°) temperatures clearly has an unfavorable effect both on
the general condition of animals and on distortion of the temperature
relations, leading in the first instance to pronounced hypothermia and
premature death and, in the second, to hyperthermia and death. Of in-
terest is the fact, observed on varying the external temperature, that
a temperature of 30° favorably affects both the general condition and
the maintenance of temperature relations on the correct level. Tempera-
ture fluctuations in the organs investigated were slight and many func-
tions of the organism were not markedly depressed.
Thus, on the basis of Ye. A. Kartashevskiy ' s calorimetry investi-
gations (1908) and our own findings, it is fair to say that general hypo-
thermia and impaired normal temperature relations between the organs and
23
tissues in hypo- and hyperoxemia result chiefly from impairment of the
thermoregulatory function of CNS, which affects not only the metabolic
processes in the individual organs as well as in the organism as a
whole, but also the blood supply.
The importance of the CNS in impairment of thermodynamics was con-
firmed by our second series of experiments on decorticated and decere-
brated animals exposed to oxygen deficiency and poisoning. This problem,
unfortunately, has not been properly elucidated in medical and biologi-
cal journals, except for some isolated data on impairment of the thermo-
regulatory function of the CNS in hypoxemia (Arkhangel 'skaya, 19*1-9;
Avtonomov and Krelin, 1955)- Our observations showed that the drop in
rectal temperature in decerebrated and decorticated rabbits was gradual
and slight as compared with the rapid and sharp drop in intact animals.
The experimental data indicate that extirpation seems to disrupt the
adaptation functions of the organism.
Progressive hypothermia caused by the different partial pressures
of CI- seems to us to be an active process related to signals reaching
the cerebral cortex along the nervous pathways from the chemo- and pres-
soreceptors through the hypothalamic region. However, this active drop
in temperature under the influence of oxygen deficiency and poisoning is
lost or, at any rate, is sharply limited by removal of the superincum-
bent centers .
It follows from the experimental data that removal of the cerebral
cortex causes a loss of adaptation changes in metabolism and a loss of
influences on sensitivity to insufficient or excess Op, which in turn
results in increased tolerance of hypoxemia and hyperoxemia. This agrees
with the data obtained some time ago by V. V. Strel'tsov and A. G.
Zhironkin.
Progressive hypothermia in hypoxemia and hyperoxemia can be under-
stood only in the light of I. P. Pavlov's theory of a constant interac-
tion between the cerebral cortex and tissue processes in the viscera..
Presumably the heavy flow of impulses from the interoceptors to the
cerebral cortex in hypoxemia and hyperoxemia, in response to which the
sensitivity of the cortex changes and some secondary reactions to con-
trol oxygen deficiency and poisoning appear, has a different significance
in an operated animal. Two kinds of phenomena may be significant here:
(l) the portion of the CNS most sensitive to a change in the partial
pressure of oxygen (cortex) is missing; and (2) there is complete disin-
tegration of functions, resulting in each tissue system adapting inde-
pendently of one another to the insufficiency or excess of oxygen.
The following conclusions can be drawn from the data presented above :
2h
(a) A change in the partial pressure of Op in the atmosphere sig-
nificantly influences the thermoregulatory function of the body. Pro-
gressive hypothermia arises and impairs the normal temperature relations
between the various organs and tissues.
(b) The environmental temperature is an important factor in main-
taining thermoregulation at a suitable level in hypoxemia and hyperoxemia.
(c) The external temperature has a favorable effect both on thermo-
regulation and on a number of other functions by increasing resistance
to the different partial pressure of Op.
(d) Adaptation of the animal organism in general and thermoregula-
tion in particular to the different partial pressure of O2 is effected
by the highest division of the CNS--the cerebral cortex.
(e) The mechanisms responsible for the development and course of
temperature impairment in organisms experiencing an insufficiency or the
toxic effects of oxygen are alike.
MEDICAL SERVICE FOR THE CIVIL AIR FLEET OF THE USSR
A. S. Asribekov
The organization of health services and the clinic system for flight
personnel of the civil air fleet (CAF) dates back to 1930. The growing
network of medical installations in various CAF subdivisions revealed
the need to organize and direct such installations on air transport.
This was done in 1938- The various subdivisions are now served by air
health departments and medical services of the larger branches, medical
units of flight sections, health stations, dispensaries, polyclinics,
hospitals, preventive clinics, medical examination commissions, and de-
partment of aviation medicine.
The commercial activity of the CAF and its prospects shape and spe-
cialize the network of medical installations operated by the CAF. They
have led to the organization of aviation medicine laboratories and, in
1956, of pressure laboratories, centers for functional diagnosis, etc.
The development of aviation technology and introduction of multi-
place turbojet and turboprop passenger planes (TU-lOl*, TU-11^, TU-I35,
IL-18, AN-10, AN- 21*, etc.) and a series of helicopters (MI-1, Ml-k, MI-6,
25
K-15, K-l8, V-2, etc.) have made it necessary to solve problems concern-
ing working conditions and the effects of some flight factors to ensure
the comfort of passengers and crew.
The extensive work done to create the conditions whereby people of
different ages and states of health could fly in comfort enabled the
CAF to inaugurate large-scale passenger jet flights, this was the first
airline in the world to do so. The experience has been that most pas-
sengers, regardless of age or state of health, feel well on these flights.
An important safeguard is the proper training of the crew. The
medical service wants flight personnel to function normally, have rest,
good food, and adequate sleep before flying.
In view of the great practical difficulties in determining whether
a pilot is functioning normally just before a departure and is capable
of doing his work efficiently, we must steadily increase the quality of
medical examinations by expert commissions, doctors in flight units,
airport health stations, and preventive clinics.
Large-scale passenger travel, which has brought about numerous
arrivals and departures of planes in most airports and the presence of
many planes in the air on scheduled flights, requires an efficient medi-
cal service if the CAF is to succeed. This has made it necessary to pro-
vide specialized training for CAF doctors at a department of aviation
medicine. However, the successful performance of CAF's tasks--the in-
troduction of high-speed multiplace turbojets and turboprops flying at
high altitudes over the USSR and between continents, the wide use of air-
planes to spray poisons for agricultural purposes, and the need to pro-
tect flight and ground personnel while doing so--all these are confront-
ing the medical service with problems and subjects for research:
(a) Preparation of physiological-hygienic standards and require-
ments for new kinds of air-passenger procedures.
(b) Physiological-hygienic evaluation of passenger planes while they
are being tested.
(c) Devising of hygienic and preventive measures to ensure the
safety of all CAF planes in any climatic zones regardless of weather
conditions .
(d) Analysis of the causes of, and predisposing factors in, air
accidents and development of preventive measures.
(e) Clinical-physiological study of flying and engineering person-
nel under various conditions in order to set up physiologically sound
standards to govern working conditions, rest, and eating for efficient
and sustained performance of their duties.
26
(f) Working conditions of personnel engaged in using agricultural
poisons in order to devise hygienic measures to improve the conditions
and prevent poisoning.
(g) Problems in the theory and practice of medical examination of
students and flight personnel with a view to prolonging the period of
flying efficiency and protecting their health.
(h) Problems concerned with flight hygiene and airport service to
ensure flight safety.
(i) Air travel of passengers of different ages and states of health
to work out prophylactic measures.
(j) Devising of methods of saving crewmen and passengers under
different flight conditions.
(k) Preparation of a methods manual for aviation medicine labora-
tories of the CAF.
(l) Coordination of research in the field of civil aviation medicine
in the USSR and in the democratic countries.
(m) Working up of hygienic requirements and standards for projected
airports, repair shops, and training installations of the CAF.
(n) Problems whose solution is required by the operations of various
CAF units.
The CAF recently celebrated its UOth anniversary : The plans for its
expansion in the next few years are well known. The medical service of
the CAF will have to grow accordingly. Improvement of the service is
keeping pace with the progress of aviation technology.
LABOR HYGIENE IN THE SPRAYING OF CHEMICALS FROM CIVILIAN AIRPLANES
T. A. Asribekova
1. The spraying of chemicals from airplanes to control agricultural
pests and diseases is becoming increasingly important. The civil air
fleet has been doing this since 1925, when it was first utilized to con-
trol locusts. In 1928 I. R. Fomenko and in 1929 V. I. Brumshteyn and
0. G. Dukel'skaya were the first to study the working conditions prevail-
ing on such projects. Their reports laid the foundation for research on
27
labor hygiene in connection with the use of insectofungicides from air-
planes. M. V. Zakharova and S. I. Slonevskiy (1937) described the aerial
dusting of bodies of water with arsenic salts to combat malaria. The
authors presented data on the amount of arsenic present in the air of
the working areas, on clothing, and on skin of the hands. They recom-
mended appropriate prophylactic measures.
2. During the first few years after World War II, investigations
in this field continued. At this time reports were published by aviation
physicians P. G. Levsh (19U8), N. V. Natanzon (19M3), and A. S. Asribekov
(19U8, 19^9); who analyzed the working conditions of special-purpose air-
planes and described changes in the health of the pilots and technicians.
3. In 19^9? following generalization of the research on labor
hygiene, A. I. Belousov, Ya. F. Samter, and M. S. Shtromberg prepared
instructions for practicing physicians concerned with the use of chemicals
from airplanes.
14-. The use of new insecticides like DDT and Lindane made it neces-
sary to study the working conditions of fliers and technicians, devices
for individual protection from the poison, and means of preventing poi-
soning by these chemicals (A. I. Belousov, 1952, 1953)-
5. On the basis of their research on the working conditions of
pilots and technicians, D. S. Kuleshov, I. M. Geller, A. V. Chapek, A. I.
Belousov, A. V. Kaminskaya, and R. S. Slavenchinskaya (1952) made recom-
mendations on organization of their work, rest, and living conditions and
prepared instructions for medical supervision of such persons.
6. After the development of highly toxic organophosphorus insecti-
cides (thiophos, mercaptophos , methylmercaptophos, etc.) and herbicides
of the 2.4-D group (butyl ester and amine salt) and the need to apply
them from airplanes, extensive research was undertaken on the hygienic,
toxicological, and physiological aspects of these compounds and the nec-
essary prophylactic measures formulated (Yu. S. Kagan, 1957-1958; Yu. I.
Kundiyev, I957-I958; T. A. Asribekova, 1957-I958; V. A. Kryuchkova, 1957-
1958; T. S. Asribekova, 1959; I- T. Brakhnova, 1959; N. K. Statsek, I96I;
T. A. Asribekova, 1962; A. G. Vinel ' , 1962; P. V. Izbavitelev, 1962;
Kb. Z. Lyubetskiy, B. E. Gurevich, et al. (1962); A. Yakubov, 1962; T. A.
Asribekova, 1963) .
7. The investigations of T. A. Asribekova showed that the use of
organophosphorus insecticides from airplanes produces changes in the
nervous system, predominantly in the parasympathetic division of the
autonomic nervous system, a decrease in cardiovascular tone, and changes
in the peripheral blood, mainly enzymic in nature, and in some morpho-
logical and physicochemical properties. As a result of these investiga-
tions, prophylactic and therapeutic measures were proposed, the technical
Ill II HUH 111 II III III III I I
28
requirements and experimental models of a respirator were developed, and
proposals were made for design changes in the sprayer of the AN-2 and
YaK-12 airplanes and in the ventilation system of the V-2 helicopter.
8. The working conditions of those handling pest control chemicals
(ground and aerial methods) were also studied by I. T. Brakhnova, G. A.
Voytenko, 0. N. Kurkatskaya Yu. S. Kagan, V. I. Osetrov, Ye. I. Spynu,
N. K. Statsek, and others (the compounds investigated included metaphos,
polychlorpinene, hexachlorcyclohexane, mercaptophos, heptachlor, thio-
phos, and methylmercaptophos) .
9- Despite the increased amount of research on the hygiene and
toxicology of the insectofungicides applied aerially, much more is
needed to satisfy practical needs. In I962, some 30 insecticides were
used this way, but the number rose to 60 in 1963. The total amount of
chemicals has also been increasing. Whereas collective and state farms
received about 50,000 tons of the chemicals in 1950 , they received
596,000 tons in 1962. In view of the effectiveness of the aerial method
and possibility of treating large areas in a short period of time, it is
expected that the technique will gain in popularity with every passing
year.
10. Concentrations of the highly toxic organophosphorus compounds
exceed permissible limits in the cockpit of the AN-2 and YaK-12 airplanes
and MI-1 and KA-15 helicopters. The pilot is forced to use a respirator,
which hampers him in performing operations requiring considerable atten-
tion and effort.
11. The bright prospects for aerial spraying and for the continued
synthesis of new toxic insecticides require better devices for supplying
the cockpit with purified air through special filters plus mechanization
and hermetic sealing of the processes involved in opening and sealing the
packages containing the chemicals, and in preparing and priming working
solutions in airplanes and helicopters, in order to create safe working
conditions for the flight and ground personnel.
PHARMACOLOGICAL PROPHYLAXIS AND THERAPY OF AIRSICKNESS
Z. A. Astakhova, Ye. P. Belogortseva, M. D. Kruglik and
P . I . Syabro
Studies were made on passengers flying from Dnepropetrovsk to
Kharkov, Zaporozh'ye, Rostov, Mineral 'nyye Vody, Krivoy Rog, Aller,
29
Kiev, Moscow, etc. and. on through passengers. Drugs were prescribed both
to prevent and to treat airsickness. Combinations of preparations pro-
posed by the Pharmacology Department, Dnepropetrovsk Institute, were
used:
(a) "Platybrin", consisting of a double tartrate of platyphylline -
5 mg, caffeine with sodium benzoate and sodium bromide - 15 g each.
(b) "Platybrin" No. 2, in which the caffeine and sodium benzoate
was replaced with 0.1 g of pure caffeine, and sodium bromide was replaced
with potassium bromide in the same dosage of 0.15 g each.
(c) The mixture "PPKB", in which 0-3 g of papaverine hydrochloride
was added to the ingredients of "Platybrin" No. 2.
(d) "FPPKB", in which 5 mg of amphetamine was added to the mixture
"PPKB".
(e) The mixture "Platkof", consisting of 5 mg of platyphylline bi-
tartrate and 150 mg of caffeine and sodium benzoate. This drug was given
to persons known to be allergic to bromides.
All the drugs were prescribed in prophylactically tablet form, 30-1*5
minutes before departure, both on an empty stomach and after eating. They
were prescribed for therapeutic purposes in the airport health unit after
symptoms of airsickness developed. The observations were begun in i960.
Three hundred and six persons known to have suffered previously from
airsickness were under observation. In Ikk cases the drugs were pre-
scribed for the same passengers both for prophylactic and for therapeutic
purposes. The age composition and sex of the individuals are shown in
Table 1.
Table 1. Age Characteristics of the Persons Under Observation
Purpose of
drugs
Age
Sex
Up to 11-20 21-30 31 -U0 1*1-50 51-60
10 years years years years years years
Total
Males
Females
Pr ophyla ct i c
Therapeutic
Prophylactic
Therapeutic
2 2 29 37 18 6
1 3 27 29 11* 3
3 5 1*7 58 19 U
2 1* 1*7 53 19 8
9h
77
11*6
133
30
We used the following as criteria of effectiveness of the drugs :
the individual's impression of his own condition and manifestation of
autonomic disorders --nystagmus, nausea, and vomiting. Sometimes the
pulse, blood pressure, and number of respirations were measured. When
passengers did not return to the airport, evaluations were made from
records of the flight stewards and letters from the persons themselves.
FPPKB, which includes amphetamine, was not prescribed for elderly
persons or for those with symptoms of hypertension. Eesults of the ob-
servations in which the drugs were prescribed to prevent airsickness are
summarized in Table 2.
Table 2. Effectiveness of Prophylactic Administration
of the Drugs
No. of
Effectiveness in %
persons
CO
a
•H
-P
No.
Drug
2
u
<d
CD
O
-p
>>
u
-p
co
-P
O
CD
tin
CO
<u
cfl
bO
<w
CD
<4H
.H
Ch
a
CD
CO
■H
O
H
co
•H
CD
cd
CD
ti
•H
M
CD
,H
S
•
-P
T)
o3
CD
O
X
n3
cS
■H
^
P-4
a
w
CO
(-P
co
1
Platybrin
35
h5
150
25
^5
23
7
None observed
2
Platybrin
No. 2
22
28
50
26
^7
20
7
The same
3
PPKB
12
38
50
30
51
H
5
11
k
FPPKB
13
17
30
30
57
10
3
ti
5
Platkof
12
18
30
22
38
25
15
IT
It is evident from Table 2 that the prophylactic use of "Platybrin"
and "Platybrin 2" bad an excellent or good effect in 70-73 percent of
the persons observed. These figures almost coincide with those for
"Platybrin" (Syabro's mixture) prescribed to prevent seasickness (E. A.
Okunev, Klinicheskaya meditsina (Clinical Medicine), I958, No. 9, p.
72).
31
If the bromide was left out of "Platybrin", it was less effective.
For example, "Platkof" had a protective effect in 85 percent of • the
cases, an excellent or good effect in only 60 percent.
The combined drugs PPKB and FPPKB were more effective in preventing
airsickness. PPKB and FPPKB had an excellent or good effect in 8l or 87
percent of the cases, respectively. It is also worth noting that these
combined drugs had no side effects.
When drugs were ineffective, it was apparently because they were
taken late or after eating. Additional observations will be necessary
to supplement the small number of cases studied.
The next series of observations concerned the effectiveness of the
drugs in the treatment of those passengers already suffering from air-
sickness. The data are summarized in Table 3.
Table 3. Therapeutic Effectiveness of the Drugs
No. of
Effectiveness in
*
persons
to
■H
-P
n3
i>
fH
>i
co
1)
f-i
-P
No.
Drug
CO
O
-p -p
a
OJ
en
a> a3
bO
Ch
OJ
<Vh
H Ch
a
<D
to H
H CO
•H
0) cri
CD Tj -H
^
(1)
h a
■
O O -P
O
■d
cfl 0)
X O cd
cd
•H
S P-H
S
pq O CO
J
CD
1
Platybrin
39 3k
93
18 te 36
1+
None observed
2
Platybrin
No. 2
18 33
51
20 k3 3k
3
The same
3
PPKB
9 22
31
23 57 19
1
TT
k
FPPKB
11 2k
35
28 57 19
-
1!
The effectiveness of the drugs was evaluated l-l/2 hours after ad-
ministration. The effect was considered (l) excellent when all the
symptoms of airsickness disappeared and the passenger again felt cheer-
ful, with normal pulse and respiration, (2) good when all the symptoms
32
disappeared and the pulse and respiration were within normal limits, but
a sensation of slight fatigue persisted, (3) satisfactory when autonomic
phenomena completely disappeared but a sensation of fatigue or sluggish-
ness remained, and (h) negative when the passenger was suffering from
some other disease (cardiovascular insufficiency, gastrointestinal
disease) .
Conclusions
1. The drugs can be arranged in ascending order of effectiveness
in preventing and treating airsickness as follows : platybrin and platy-
brin 2, PPKB (platyphyllin-papaverine- caffeine and sodium bromide), and
FPPKB (amphetamine-platyphyllin-papaverine-caffeine and sodium bromide ) .
2. The combined drugs --platybrin and the mixtm ss PPKB and FPPKB--
are recommended for prevention and treatment of airsickness.
THE DOG SPLEEN RESPONSE TO LATERAL ACCELERATION
Yu • I . Af ana s ' ye v
Numerous experimental investigations of animals in vibration test-
ing units and centrifuges and of animals on spacecraft showed that the
blood system reacts quickly to acceleration (A. M. Galkin and co-authors,
1958j B. G. Bugrov and co-authors, 1958j !• !• Kas 'yan and co-authors,
1962; others). The changes noted are not merely the result of redistri-
bution of blood, they also reflect impairment of hematopoiesis (M. A.
Arsen'yeva and co-authors, 1962j N. A. Yurina and N. I. Suprunenko, 1963;
others). The most drastic changes in the organs are caused mainly by
mechanical factors. The investigations directed by Prof. V. G. Yeliseyev
showed (V. G. Yeliseyev, Ye. F. Kotovskiy, and Yu. N. Kopayev, 1963) that
the extent of injury is related to the size of the organ and amount of
blood flowing in it (liver, lungs, etc.).
According to Gerrat (1957); "the dog spleen is an organ whose main
function is the deposition of blood. It is fair to assume, therefore,
that the accumulation of a large amount of blood in the spleen during
acceleration may bring about changes similar to those in other organs.
However, in view of the spleen's capacity for rapid and powerful con-
traction, we can make no a priori claims about the nature of these
changes, especially since the organ has hematopoietic, metabolic, and
other functions besides deposition of blood. For this reason we undertook
33
to investigate reactive changes in the spleen of dogs subjected to accel-
erations .
Method
Experiments were performed on 28 stock-bred dogs. All the animals
were subjected to single lateral (chest-back) accelerations, of different
intensity and duration. There were two series of experiments. In the
first, the action lasted 3 minutes with an acceleration of 8 g. In the
second series, the animals experienced an acceleration of 12 g for 1
minute. Each series included Ik animals, all of which were immunized
against plague 2 weeks before the experiment.
The animals were killed with ether fumes at different times during
the experiment--l hour, 1, 3, 7, 15, 30, and 60 days after the overload.
A razor was used to excise fragments from the ventral and dorsal ends of
the spleen. These were fixed in Zenker's formalin and Carnoy's fluid.
The material was embedded in paraffin and celloidin. Sections were
stained with azure-II-eosin, methyl green pyronin by Brachet's method,
for connective tissue by Mallory's method, and for ionic iron by Tirmann's
method .
Results
Owing to the varied functions and complex structure of the spleen,
the results of the experiments were evaluated from the condition of three
constituents of this organ: (l) sustentacular-contractile apparatus
(capsule and trabeculae), (2) vascular bed, (3) lymphoid tissue.
Analysis of the experimental material showed that the changes in the
spleen following accelerations of 8 g for 3 minutes and of 12 g for 1
minute were more or less the same, but the duration of the action seems
to be the determining factor. All the changes in the histological struc-
ture of the spleen were usually more pronounced and persistent in the
first series of experiments than in the second.
Gross inspection of the spleen soon after the animals were sacrificed
( 30 -1+0 minutes later, when the abdominal cavity was dissected) revealed
that the capsule had contracted. Here and there (where the large tra-
beculae branched out) the capsule was retracted like a funnel, another
indication that the smooth-muscle cells of the trabeculae had contracted.
Microscopic examination revealed that the smooth-muscle cells of
the capsule and trabeculae were contracted in wavelike fashion so that
the trabeculae were alternately enlarged and contracted throughout.
3^
Besides contracted muscle elements, there were degenerative changes
in individual smooth-muscle cells, especially in the animals used in
the second series of experiments. The protoplasm of these cells was
vacuolated, their nuclei wrinkled and crowded to the periphery. These
processes were most marked after 3 days .
The red pulp on the first day after the overload was hyperemic in
all the dogs. Blood filled all the sinuses and diffusely permeated the
reticular stroma of the organ, making it almost impossible at times to
discern the boundary of the vascular bed.
The endothelium of the blood vessels (trabecular, central arterial)
after 3 and 7 days revealed vacuoles in the cytoplasm, pycnotic nuclei
with sloughing off of the endothelial layer, and some ruptured blood
vessels. These changes were particularly marked in the animals used in
the second series of experiments. Thrombi appear later in the blood
vessels, generally in the trabecular veins. Destroyed smooth-muscular
cells were noted in the arteries .
Changes in the ionic iron content of the pulp were unstable through-
out the experiment, but the first day (after 1 and 2k hours) the amount
of hemosiderin was usually higher. The pigment was found both in macro-
phages and reticular cells and between the cells, generally around the
lymph nodes and trabeculae. It is very difficult, however, to speak
more definitely about the dynamics of the iron- containing pigment in
the spleen because the animals were of different ages.
The lymph nodes of the animals in the first series shrank and re-
leased small lymphocytes an hour after the experiment started. The
emptying of the nodes was a persistent phenomenon and even after 30 days
they contained very few small lymphocytes. Mitotic figures were very
rarely seen in the lymphoblasts .
In the second series of experiments, the lymph nodes scarcely
changed. In the red pulp, however, the number of lymphocytes increased
during the first and second weeks.
By the end of the first month after the start of the experiment,
the lymph nodes, mainly in the animals of the first series, contained
"hyperchromic cells" (M. A. Arsen 'yeva and co-authors, I962), which stained
intensely with azure-II.
After 2 months the microscopic structure of the spleen returned to
normal .
35
Discussion
The results of the experiments show that lateral accelerations in
a chest-back direction differing in intensity and duration cause defi-
nite changes in the histological structure of the spleen. However, in
analyzing the data it is important to differentiate between the effect
of the experimental accelerations and that of the ether fumes when the
animals were sacrificed.
The spleen, known as a blood depot, ejects it into the peripheral
blood channel under the conditions of intense gas exchange or, contrari-
wise, when insufficient oxygen enters the organism. Consequently, when
the animals were killed with ether and conditions of an oxygen defi-
ciency were created, it was to be expected that the erythrocytes present
in the red pulp would be ejected into the peripheral blood channel.
This compensatory reaction to the oxygen deficiency explains, in our
opinion, the fact that the smooth-muscle cells of the trabeculae and
capsule were contracted in more or less wavelike fashion regardless of
the time the animals were sacrificed. Yet there were also degenerative
changes in the smooth-muscle cells of the trabeculae, especially in the
second series of experiments. These were apparently due to the accelera-
tions.
Impairment of the structure of the endothelium in the early part
of the experiment (3rd and 7th days) and subsequent thrombogenesis were
undoubtedly caused by the accelerations. Otherwise, similar changes would
have been found at other times in the course of the experiment.
Conclusions
1. Accelerations (8 g - 3 minutes, 12 g - 1 minute) produce de-
generative changes in the endothelium of the blood vessels of dogs,
smooth-muscle cells of the trabeculae and capsule of the spleen, rupture
vascular walls, and cause thrombogenesis therein.
2. Lymph nodes are emptied the first day after acceleration and
proliferation of lymphoblasts is inhibited. Mitotic activity is restored
slowly in lymphoid tissue.
3. Accelerations (as in the first series of experiments) exert a
more potent influence on lymphopoietic tissue, whereas brief but more
intense accelerations (as in the second series) result mostly in degen-
erative changes in the smooth-muscle cells of the capsule, trabeculae,
and wall of the blood vessels.
h. The histological structure of the spleen returns to normal 2
months after exposure to accelerations .
36
MODERN AVIATION AND PROBLEMS IN ENSURING THE MEDICAL
SAFETY OF FLIGHTS
A. N. Babiychuk
(The text of the report is not available)
THE EFFICIENCY OF MAN EXPOSED TO RADIAL ACCELERATION AND
BREATHING OF OXYGEN AT AN EXCESS PRESSURE
V. I. Babushkin and V. V. Usachev
Depressurization at altitudes above 12,000 m and resultant lowering
of barometric pressure in the cabin of an airplane automatically switch
the oxygen apparatus to supplying oxygen for breathing at an excess pres-
sure and actuate the altitude- compensating suit. Under such conditions
flying may be associated with the appearance of accelerations so that the
pilot will experience the total effect of the aforementioned factors,
the physiological influence of which has not been elucidated in the
literature to which we had access. In this connection we undertook to
study the effect of radial acceleration on the human organism breathing
oxygen under pressure.
The investigations were conducted both in a centrifuge and under
flight conditions. In the former, the rate of cardiac contractions and
respiration were recorded and a study was made of various movements
simulating some of the pilot's work in controlling his plane and his
actions in an emergency situation. On actual flights, recordings were
made of the rate of cardiac contractions and respiration, altitude and
speed, and intensity of acceleration.
We found that an altitude -compensating suit (ACS) increases toler-
ance of accelerations by 0.5-1 g. At the same time the increase in the
cardiac rate was less than after accelerations of the same intensity
but without the use of an ACS. A study of pilot movements showed that
an ACS without pressure in its tension system has no appreciable effect
on the coordination of movements. With acceleration and breatning of
oxygen, the cardiac rate increased by 26-60 beats per minute over the
initial values. Switching to breathing of oxygen under pressure ( 350 mm
HoO) reduced the cardiac rate by 16-U2 beats per minute. Use of a G-
suit under these conditions caused an even smaller increase in this
index- -8- 30 beats per minute.
37
With breathing at this pressure but without acceleration, exhala-
tion lasted 2.2-4 seconds, inhalation- -1.2-1. 9 seconds. During an ac-
celeration of 4 g, exhalation varied in duration from I.6-3.2 seconds
inhalation- -1-1. 8 seconds, i.e., approximately equal to the original
indices.
Analysis of the data obtained after an acceleration of 4 g and
breathing of oxygen at a pressure ranging from 400 to 1000 mm HJD with
the use of back pressure (ACS) revealed that the physiological effect
resulting from the use of a functioning ACS with acceleration scarcely
differed from the above-noted phenomenon of smaller functional changes
when a G-suit was worn. For example, the increase in cardiac rate
during an acceleration of 4 g with breathing at a pressure of 400 mm
Ho0 and wearing of an ACS ranged from 10- 32 beats per minute.
Under the same conditions, but with wearing of a G-suit, the in-
crease in cardiac rate was 8-3O beats per minute. It is interesting to
note that the compensating effect of the ACS during accelerations in-
creased as pressure rose in its tension system. The oral reports of
the subjects indicate that during accelerations, even at high excess
pressures (800-1000 mm H ? 0), il became easier to breathe than when there
was no acceleration. The use of a G-suit helped breathing even more by
facilitation of exhalation.
The results of our investigations of movements under the conditions
of acceleration and breathing at an excess pressure with the use of an
ACS showed that the subjects experienced considerable difficulty in
doing their routine work, as manifested in the longer time required for
performance of the individual components of a motor act. These changes
in movements were reflected in various ways in our investigation of move-
ments of the control stick and foot levers involved in controlling an
airplane. Interpretation of the coordinograms revealed that when the
ACS was functioning, the performance of tasks was approximately l-l/2
times less precise. With exposure to an acceleration of 4 g, movement
coordination changed even more. However, movements by the "eye sector"
scarcely changed.
The results of our centrifuge investigations of the efficiency of
human beings exposed to accelerations and breathing of oxygen at an
excess pressure were paralleled by those obtained under flight conditions.
In discussing the data, we must begin by stressing the fact that in
breathing oxygen under pressure, with the wearing of a G-suit and ex-
posure to prolonged accelerations, there are less pronounced changes in
respiratory and cardiovascular function than when oxygen is breathed
under normal pressure. A comparison of these findings with flight re-
ports indicating that breathing under these flight conditions is easier
suggests that prolonged acceleration activates additional compensatory
38
mechanisms that facilitate breathing, exhalation in particular. Besides
fewer changes in respiratory function, the increase in number of cardiac
contractions is less pronounced. It seems to us that the increase in
tone of the skeletal musculature, specifically, the respiratory muscles
and the muscles used in the prelum abdominale, is the principal mechan-
ism underlying the relatively small changes in the cardiovascular and
respiratory systems .
This adaptation reaction is quite similar to the special "M-l"
technique (Lambert, Wood, et al., 19^5-19^6; Landis, I9U8; others)
whereby intraabdominal pressure is considerably increased, resulting
eventually in less marked functional changes and strengthening the
tolerance of accelerations. A summary effect, so to speak, takes place
when a G-suit is worn, causing intraabdominal pressure to increase even
more. This, in turn, leads both to easier exhalation and to decreased
stasis in the abdominal blood vessels. In time the G-suit also performs,
in part, the role of an ACS. This idea agrees with references in the
literature (N. 0. Tsybul'skiy, 1879; Garso, 1919; Youngblade and Noyes,
1933; others) to the fact that there are fewer changes in cardiac activ-
ity in case back pressure is used with acceleration.
Thus, our investigations throw some light on the efficiency of fliers
exposed to acceleration while breathing oxygen under pressure and help to
elucidate the mechanisms of compensation of physiological functions under
these conditions.
PHYSIOLOGICAL REACTIONS TO RADIAL ACCELERATION
V. I. Babushkin, P. K. Isakov, V. B. Malkin
V. V. Usachev
The physiological bases for the ideas on the effect of accelerations
on the human organism were established in the works of K. E. Tsiolkovskiy
(1878), N. 0. Tsybul'skiy (1878), V. V. Pashutin (l88l), V. I. Voyachek
(1908), A. P. Popov (1936), D. Ye. Rozenblyum (1939), V. V. Strel'tsov
(19V?) * and others. The most noted foreign investigators of the physi-
ology of accelerations include Armstrong (1935), Diringshofen (1936),
Gauer (1938), Malmejaques (19U5), Britton (1950), Lambert (1952), and
Duane (195I+).
Flight experience has dictated the need for further study of the
physiological mechanisms of action of accelerations, a more detailed
investigation of the physical fitness of fliers in curvilinear flight,
39
and the formulation of scientifically grounded, recommendations for the
creation of effective protection against this unfavorable factor. These
problems led to the performance of a series of experiments ( 1950-19^2 ),
which are partly summarized in this report.
The investigations involved centrifuge tests and actual flight, as
well as a variety of methods to study the physiological functions and
fitness of fliers.
To determine the reasons for individual resistance to accelerations,
we compared the data showing functional changes in the cardiovascular
and respiratory systems. Analysis showed that highly resistant persons
(acceleration of 6-7 g) had a marked elevation of blood pressure in the
brachial artery and increased cardiac and respiratory rates. With lower
resistance, the rise in arterial pressure was less and the increase in
pulse and respiratory rates varied from individual to individual.
The data on conditioned motor reflexes indicated primary impairment
of function of the visual analyzer. After exposure to accelerations of
"threshold" intensity, changes in these reflexes were biphasic. During
the first phase in which the time corresponded to the start of "take-off",
there was a marked increase in the latent period of the motor reflexes
to light, with a slight increase in the latent period of the motor re-
flexes to sound. During the second phase, which corresponded in time to
the appearance of visual disturbances, the motor reflex to light dis-
appeared although the conditioned reflexes to sound were preserved.
Soon afterward ( 10-15 minutes later), the magnitude of the vasomotor
conditioned reflexes decreased considerably. Sometimes there were para-
doxical reactions.
To obtain a better understanding of the role of the conditioned-
reflex component in the mechanism of development of compensatory reac-
tions , special experiments were run in which the conditions of an ordinary
experiment were reproduced, but the acceleration was no more than 1.5 g.
The subjects were not informed of the intensity of the preceding action;
it was included in the series of rotations during which the subjects were
exposed to greater accelerations. The results of these investigations
showed that arterial pressure rose insignificantly during accelerations
of 1.5 g (about 10 mm Hg) while there was a more pronounced increase in
the pulse rate (from k to 22 per minute). Consequently,, in trained per-
sons compensatory changes in blood circulation take place even before
the effect of accelerations is manifested, resulting in rapid develop-
ment of these reactions.
Some investigators (V. V. Strel'tsov, I938; M. D. Chirkin, 1937;
G. Shubert, 1937 J others) have pointed out that increased tone of the
skeletal musculature is significant in the adaptation to accelerations.
This view is based on observations showing that involuntary contraction
kO
of the abdominal muscles increases resistance to accelerations. How-
ever, no special experiments were performed to study the functional
state of the skeletal musculature during accelerations. We studied the
bioelectrical activity of the muscles of the chest, abdomen, and lower
extremities in response to accelerations of different intensities. We
found that the amplitude of the biocurrents of muscles in the lower ex-
tremities and abdomen distinctly increased during accelerations of 1-
2.5 S- However, the biocurrents of the chest (intercostal) muscles
became activated usually by more intense accelerations (3 g). The most
pronounced increase in amplitude of the muscle biocurrents occurred
during accelerations of 2 to 5 g. A further increase in acceleration
generally failed to increase the amplitude of the biocurrents and often
reduced it.
A series of experiments was performed on subjects wearing a G-suit.
The creation of pressure in the suit during accelerations caused a sharp
decrease in the amplitude of the biocurrents of the abdominal and femoral
muscles, and in some experiments they disappeared entirely.
This pattern of changes in muscle biocurrents in response to ac-
celerations is similar to the changes in bioelectric activity of muscles
observed by V. S. Gurf inkel ' et al. (1955) in static work. It is inter-
esting to note that, just as in the case of accelerations, so too in
static work, after the load reaches a maximum, the amplitude of the bio-
currents soon decreases. This similarity suggests that both cases in-
volve common mechanisms of reflex reorganization of skeletal muscle
activity.
This view was confirmed by investigations of gas exchange during
accelerations. Analysis of the experimental data showed that lung ven-
tilation increases (up to a certain point) as acceleration is intensified.
With accelerations of 5 g, lung ventilation is more than double the
original value. The use of a G-suit caused less marked changes in res-
piration. Lung ventilation meanwhile grew less than in the experiments
in which a G-suit was not worn.
With accelerations of 5-6 g, the subjects used much more oxygen--
almost twice the original amount. The percentage of oxygen utilization
by blood flowing to the lungs decreased during accelerations, but the
total consumption of oxygen grew steadily. At the same time there was a
considerable increase in the amount of carbon dioxide released so that
the respiratory quotient rose to unity and frequently slightly above.
The results of the investigation of gas exchange also showed that
during the first 5 minutes after exposure to accelerations oxygen con-
sumption remains high while the respiratory quotient remains close to
unity. These findings indicate that accelerations cause a marked in-
crease in the metabolic rate. The use of a G-suit significantly reduces
ia
oxygen consumption during accelerations. Consequently, energy expendi-
ture with accelerations of equal intensity was less when a G-suit was
worn than when it was not.
The development of compensatory reactions --increased skeletal
muscle tone, growth of functional activity of the cardiovascular and
respiratory systems --during accelerations results in greater expendi-
ture of energy. The use of a G-suit apparently removes part of the
"load" from these functional systems and thereby enlarges the physio-
logical capabilities of fliers .
TRANSMISSION OF MEDICAL INFORMATION OVER LIMITED-CAPACITY
TELEMETRY CHANNELS
R. M. Bayevskiy
Man's conquest of space is enlarging the scope of research problems
and making it necessary to increase the reliability of medical monitor-
ing because the amount of information to be transmitted from spacecraft
to the earth is growing. At the same time the greater duration and
distance of space flights is sharply restricting the possibilities of
transmitting information. Thus, it is essential for us to be able to
transmit the maximum amount of information over limited-capacity telem-
etry channels.
Information theory may provide the key to solving the problem. Ac-
tual messages usually contain a number of repetitions or information
already known. If only the essential information is extracted from a
message, it could be transmitted over telemetry channels with one-tenth
or one-hundredth the capacity of the channels required to transmit the
communication as a whole. The presence of useless along with useful
information in a message is called redundancy in information theory.
Efficient coding of medical information can be based on the elimination
of redundancy.
Let us take, for example, the transmission of an electrocardiogram
over a radiotelemetry channel, assuming continuous recording for 20
minutes. To restore the original shape of the curve requires that it be
transmitted at a speed of at least 100 dots per second with 5 percent
accuracy of quantization.
According to our calculations, an EKG contains about lj-00 binary
units per second. Therefore, about one-half a million such units of in-
formation will be transmitted in 20 minutes.
w
k2
In processing (interpreting) the resultant data, the waves and
intervals on the EKG are measured and about 10 different indices are
determined (PQ, QRS, QT, Sp, etc.). These measurements occur at an
average frequency of once a minute. Thus, 200 figures are obtained in
a 20-minute recording. If a suitable automatic device is used and fig-
ures are transmitted instead of the EKG curve, a message of 200 four-
digit numbers will contain about 5000 binary symbols, i.e., 100 fewer
than the EKG. What is important here, besides the gain in capacity of
the telemetry channel, is the fact that the information does not require
special processing and can be analyzed while the flight is proceeding.
A further reduction in the number of messages to be transmitted
from the spacecraft may be achieved with a more rational code. One
variation in coding is to transmit only deviations from previously
transmitted values. The transmission of statistically generalized
indices such as M. a. S. could be quite effective. Coding could be
even more economical if symbols indicative of a normal or pathological
state of the given index were entered into the communication channel
rather than the actual numerical indices.
Finally, we must mention the possibility of consecutive transmis-
sion of medical information instead of the parallel recording now used.
Even a simple temporary commutation of measurements would provide a
definite gain with respect to the amount of information to be trans-
mitted. If the measurements were automated, there would be primary
accumulation of data for a given period of time and then transmission
of these data. The indices measured simultaneously would be transmitted
consecutively .
The principle of producing a symbolic code through identification of
pertinent information and elimination of all the data that have no prac-
tical use was utilized to design several kinds of special medical re-
search apparatus. For example, models were made of a U-channel electro-
myograph and h- channel electroencephalograph designed to transmit infor-
mation over a single limited-capacity channel. The encoder of the
electromyograph made a count of impulses every second in each lead and
determined the integral value of the biocurrents, with the formation of
8 pulses reflecting the frequency-amplitude composition of the biocurrents
in the k leads of the electromyogram. A telemetry channel with a capacity
of about 150 bits per second is needed to transmit 8 pulses per second
with 5 percent accuracy of quantization. The transmission of k electro-
myograms without coding requires h telemetering channels with a capacity
of 2000-3000 bits per second each.
The principle of coding an electroencephalogram is based on identi-
fication of the alpha, beta, gamma, and delta constituents and determina-
tion of the integral values of the biocurrents at the output of each filter
for a period of 2 seconds and the general integral values of the biopotenials
^3
in each lead. Thus, 20 pulses reach the channel input per second. This
likewise produces an almost one-hundred-fold gain in the capacity of the
telemetry channels .
The possibility of producing a code that reflects very specific
information brings up the question of preparing special codes for medi-
cal monitoring on flights. The first such attempt was made in connec-
tion with the designing of a translation-summation instrument for simple
translation of pulse, respiration, and motor activity signals with the
recording of every 25th or 50"th pulse. In case of coincidence, the
pulses were discriminated by suitable selection of their amplitude or
width .
To solve the problems involved in medical monitoring of space
flights, V. V. Bogdanov, L. A. Kazar 'yan, A. M. Zhdanov, and the author
devised an automatic system with direct input of information that produces
a code by combining the features that characterize deviations from vari-
ous physiological parameters. The same coding principle was utilized in
a model of an indicator on diode matrices that V. Ya. Kostikova, A. P.
Kalinovskiy, and B. A. Soshin built at our suggestion. The transmission
of a symbolic code makes it possible, first, to reduce the required
capacity of the telemetry channels; secondly, to increase transmission
reliability and freedom from interference; thirdly, to increase the effi-
ciency of medical monitoring.
However, this method of constructing a symbolic code is very ele-
mentary and is useful only at the first stages of the work. More effec-
tive coding requires the use of statistical methods, specifically, prob-
ability and correlation principles. The probability of different signals
appearing at the input of a telemetry channel is not the same. If simpler
signals are used to transmit the most probable signals than to transmit
the least probable, a major gain can be achieved in channel capacity.
Moreover, the very distribution of probabilities between codes is of
definite diagnostic interest to physicians. Coding with prediction is
also of interest, since it is not the messages themselves that are trans-
mitted but the signals correcting the values of the signals predicted
beforehand.
There are as yet no mathematical principles for statistical coding
of medical information. However, the future undoubtedly lies with these
methods and the use of electronic computers as coding devices will be
helpful in working out new coding techniques.
kk-
DYNAMICS OF THE ELIMINATION OF CORTICOSTEROIDS AFTER
VARIOUS ACTIONS
I. S. Balakhovskiy and I. G. Dlusskaya
The efficient standardization of flying activities, like the deter-
mination of permissible intensities of other actions characteristic of
flying on modern airplanes, is considerably hampered by the lack of sen-
sitive indices for evaluating the changes brought about in the body by
an action of a given intensity.
A number of practical problems can be solved by using specific
indices that reflect changes characteristic of a particular kind of
action, such as the change in oxygen content of the blood in hypoxia,
body temperature upon cooling or overheating, impairment of blood cir-
culation due to accelerations, or breathing at an excess pressure.
However, if the mechanism by which the factor causes injury is unknown,
specific sensitive indices are usually also lacking. In this case it is
justifiable to try to find nonspecific indices which, even though not
characteristic of a concrete type of action, would nevertheless indicate
that some abnormality is present. If such an index were available, it
could be used to solve a host of problems, even those for which no re-
liable scientific approaches exist.
All this is particularly applicable to flight fatigue, emotional
stress, and prolonged isolation since the pathophysiological mechanisms
of the disorders that arise in these circumstances are almost completely
unknown .
The ideas of the Canadian scientist, H. Selye, on "stress", which
have gained wide circulation in the West these past 10 years, seem to
offer some hope for the development of such indices because Selye was
able to show that functional activity of the adrenal cortex increases
in response to a great variety of actions (Selye, 19^6; Selye and Hauser,
1956).
The investigations of N. A. Vorob'yev (i960), I. V. Fedorov and G. G.
Sturua (196I), Vance and Marchbanks (1958, i960), and Bruner and Klein
(1961) showed that flying on a modern airplane seems to stimulate the
excretion with urine of double to triple the normal amount of adrenocorti-
cal hormones and related metabolites, the so-called corticosteroids.
Therefore, without deciding beforehand the question of whether the
adrenal cortex actually performs the adaptation functions ascribed to it
by Selye, we decided to try to find out whether the function of the gland
is increased by a variety of actions.
Of the many methods of evaluating adrenal function, we chose the
following three : determination of corticosteroids and ketosteroids
45
excreted with human urine and determination of corticosteroids in rat
blood. These indices enabled us to study the dynamics of the endocrine
reactions of rats to sound stimulation and physical exertion (swimming)
as well as the functional state of the adrenal cortex in fliers and
other subjects under conditions characteristic of modern flying.
We found increased adrenocortical activity in all cases. In the
rat experiments, mere handling or very careful immobilizing of an animal
caused a sharp (more than 100-110 percent) increase in the corticosterone
content of the blood, the maximum being noted during the first half hour
after the action with a return to the original level after 1-1 l/2 hours.
The hormonal reaction to sound or physical exertion (swimming) was like-
wise pronounced (more than 150 percent); it continued throughout the ac-
tion (I5-3O minutes) and for about l-l/2 hours after it was halted. The
duration of the reaction increased if the actions were repeated on the
same day, although the maximum remained virtually the same. After daily
experiments on the same animals for a month, the quantitative and time
characteristics of the response to swimming and sound changed slightly.
Analysis of the data obtained in pressure -chamber tests showed that
the subjects were in a "pre-start" state characterized by increased ex-
cretion of adrenocortical hormones with urine before the test. The
amounts were considerably (by 100-150 percent) in excess of those noted
in the same persons on the days when there were no experiments. In some
instances maximum excretion of hormones occurred after rather than during
the action.
Examination of flying personnel completing short or long flights
under different conditions showed that during flights marked by unusual
difficulties more corticosteroids were excreted than during ordinary
flights (increases of 300-400 percent and 40-80 percent, respectively,
over the original level). Sometimes maximum excretion occurred after
the flights, just as in the pressure -chamber tests.
Examination of parachutists showed that more hormones were excreted
during jumps than on control days or days of cancelled flights. The
most significant fact here was the increased excretion of corticosteroids
at night after jumps.
Our findings indicate that a nonspecific hormonal reaction of the
adrenal cortex actually takes place after a great variety of actions.
It is highly complex in nature and is activated by a very sensitive
neural mechanism. The reaction lasts for a day or less, and its inten-
sity does not exceed normal limits.
k6
EFFECT OF ACCELERATIONS ON THE GROWTH OF LIVING BEINGS
V. I. Baranov, A. A. Gyurdzhian, M. A. Lomova, L. A. Radkevich,
L. T. Tutochkina, T. A. Fedorova, L. P. Furayeva,
S. S. Khnychev and N. S. Artem'yeva
The part played by gravitational forces in the growth and activity
of living beings is a subject of major general biological interest.
A special rotating device was designed and assembled for the pur-
pose of raising animals under conditions involving prolonged exposure
to acceleration. The intensity of centripetal acceleration could be
increased from O.k to 5.0 g by changing the rotation rate and distance
of the container with animals from the center of rotation (maximum
distance I35 cm). The rats were rotated in containers made of plexiglas,
and their behavior was recorded by a movie camera fastened to the axis
of the stand.
Using a control board, we were able to select the desired rotation
rate, provide suitable light for the moving pictures, and record 5 phys-
iological functions in specially trained animals. Simultaneous rotation
of the stand and containers around the axis created the conditions for
Cariolis acceleration to develop. The latter was also in effect while
the animals were running. Running could be stimulated from the control
board by putting food into the feed boxes and turning on bulbs (condi-
tioned food signal) found on one of the containers.
The experiments were performed on white laboratory rats exposed
from birth to k-6 hours of rotation daily, except Sundays . The inten-
sity of centripetal acceleration was 1.5 - 3 S- The litter was divided
into two groups --experimental and control--and put under the two females
that had given birth to the rats at approximately the same time . The
following biological and biochemical methods were used to investigate
the animals :
(a) General clinical observation of their condition, behavior, skin,
and growth.
(b) Regular weighing (every 3 days).
(c) Hematological investigation (N. I. Suprunenko).
(d) Comparison of the behavior and coordination of movements of
the animals during rotation.
(e) Biochemical analysis of blood- -amount of nonesterified fatty
acids, total protein, protein fractions, and serum mucoids in the plasma
(M. A. Lomova and L. T. Tutochkina).
hi
(f) Biochemical analysis of urine- -Dische-positive substances,
total nitrogen, and creatine- creatinine (T. A. Fedorova, L. P. Furayeva,
and S. S. Khnychev) .
(g) Periods of sexual maturity, course of the estrus cycle in
females, regenerative processes (N. S. Artem'yeva).
(h) Some indices of the reaction of the vestibular apparatus to
adequate and inadequate stimuli (N. N. Livshits and Z. I. Apanasenko).
Some 200 experimental and control rats were used. In addition,
several hundred intact animals were investigated for changes in selected
biochemical indices in response to acceleration.
At the end of the experiments, a comparison was made between the
reaction of the experimental and control rats to a single exposure to
brief intense accelerations of 5, 10, and 20 g, with observations on
the survival rate, biochemical, and hematological indices of the blood
and urine.
The general condition of the experimental rats did not differ from
that of the control. While being rotated the animals were able to move
around and take food. Under similar rotation conditions the control
animals sat, bunched together, and looked helpless. Wo differences
were noted between the two sets of animals in tolerance of lethal ac-
celerations .
The experimental rats lagged considerably in weight, achieving only
60-80 percent of the weight of the control between the 20th and 50th
days (the weight difference eventually decreased); they showed signs of
anemia: erythrocyte count, leukocyte count, and hemoglobin concentration
were 89.6, 93. h.^ and 99.1 percent of the level recorded for the control.
The albumin content of the blood was somewhat low, while the globulin
and serum mucoid content was high, resembling changes of degenerative
character.
The rats exposed to acceleration daily, excreted appreciably less
Dische-positive substances ( k£> percent), total nitrogen (62 percent),
creatine ( 31 percent), and creatinine (66 percent) than did the control.
Finally, the experimental females exhibited marked impairment of
the estrus cycle, as shown by lengthening of the resting phases and by
shortening and indistinctness of the estrus phase. However, there were
cases of normal gravidities and births in both groups of animals. Re-
generation of the ovaries after they were resected was likewise the
same in the control and experimental rats .
The reaction of the experimental rats to v single intense acceleration
was highly interesting. In several series of experiments, a single
U8
exposure to an acceleration of 5, 10, or 20 g produced biochemical
changes of the stress type in the control rats :
(a) Marked increase in concentration of nonesterified fatty acids.
(b) Changes in the protein fractions and serum mucoids- -reduction
in content of the latter and increase in the albumin-globulin ratio
after moderate acceleration (5 g); increase in serum mucoids and de-
crease in the albumin-globulin ratio after high acceleration (20 g).
(c) On the second day after acceleration the daily urine exhibited
increased excretion of Dische-positive substances, total nitrogen, and
creatine- creatinine .
(d) Changes in the estrus cycle in the females, as shown by a
lengthening of the resting phase after moderate acceleration (5 g) and
lengthening of estrus after high acceleration (20 g).
A single exposure to intense acceleration produced some effects that
differed from those in the control :
(a) The increase in concentration of nonesterified fatty acids set
in later and lasted proportionately longer.
(b) The biochemical changes were less pronounced.
(c) The increased content of Dische-positive substances, total
nitrogen, and creatine-creatinine in the urine were also less pronounced
than in the control animals .
Thus, our investigations show that gravitational conditions exert a
complex and multisided effect on various physiological processes (growth,
development, metabolism, estrus cycle, etc.). Functional tests (single
exposure to intense acceleration) revealed several differences in metab-
olism between the experimental and control animals.
The idea that under conditions of increased gravitation small ani-
mals develop as a result of practical adaptation processes while large
animals are produced by reduced weightlessness must be considered an
oversimplification. One of the probable factors is that animals find it
difficult to obtain and digest food under conditions of increased gravi-
tation. In some of the last experiments, both the experimental and the
control animals were completely deprived of food during the hours of
rotation. The differences between the two groups of animals in weight,
blood proteins, and some other indices were much less pronounced in
these series of experiments.
i
h9
We are still far from complete understanding of the mechanism of
action of gravitation on vital processes. It is a problem that urgently
calls for further study.
LEADING TRENDS IN AVIATION AND SPACE OPHTHALMOLOGY
V. V. Baranovskiy
The value of keen eyesight to airplane pilots and astronauts can
scarcely be exaggerated. We need only note that some 90 percent of all
the information from the external environment reaches man through his
visual analyzer.
The rapidly increasing sophistication of airplanes has given rise to
new flying conditions and complicated the task of fliers. Yet the func-
tional capabilities of the human eye have scarcely changed. It is prob-
ably worthwhile, therefore, to outline some of the directions in which
aviation and space ophthalmology should proceed.
There are several such directions and they are usually inter-
twined when it comes to dealing with practical problems. One of them
is to determine the maximum functional capabilities of the eye in con-
nection with the physical and dynamic factors involved in flying. There
is obviously need to determine not only the permissible intensities of
the individual factors but the possibilities, for training visual func-
tions. Experimentation along these lines has revealed what maximum
permissible accelerations should be: the absence of pronounced effects
from weightlessness, the main laws governing the action of vibration, etc.
But much still remains to be done on prolonged exposure to rarefied at-
mosphere, on breathing at an excess pressure, and on the effects of ac-
celeration and weightlessness.
Owing to the complicated aviation technology and systems of con-
trolling aircraft, it is important to determine not only the conditions
that ensure the tolerance of a given factor, but the conditions that are
essential for successful piloting of an airplane over a longer or shorter
period of time. A knowledge of the extent to which environmental factors
influence visual functions should make it possible correctly to formulate
the basic physiological and hygienic requirements for devices to reduce
the dependence of visual functions on external influences and ambient
factors. These requirements will ultimately determine the necessary
compromises between the capabilities of technology and the demands of
physiology.
50
The second direction relates to the creation of comfortable seeing
conditions in the plane cabin for the crew. The problems involved in
lighting the cabins of airplanes and spacecraft are unusually complex.
However, the outlook is promising for the development of cabin equipment
that will not make unduly severe demands on the light sensitivity of the
eye. It seems that there will be more comfortable conditions for visual
work in the cabin than have prevailed hitherto.
The need for more diffuse light in cabins on high-altitude flights
led an investigator (Whiteside) to recommend the use of paint with a
high reflection factor during the daytime and the installation of addi-
tional white floodlight screens to illuminate the instrument panel during
night flights .
Comfortable seeing conditions in the cabin of a spaceship are impor-
tant because natural light changes sharply during a flight. Moreover,
the change occurs periodically and is repeated at relatively short in-
tervals . A human being, therefore, has to readapt periodically to this
situation, which may impair his visual efficiency. The problem is to
determine the permissible drop in brightness that reduces to a minimum
the effect of readaptation during drops in illumination in so-called
"nighttime" operating conditions.
Human beings quite frequently suffer impairment of spatial percep-
tion and autonomic disorders while flying on modern planes. To study the
mechanisms of these phenomena and devise scientific methods of prevent-
ing them, it is useful to investigate the interdependence of the space
analyzers, which enable man to orient himself correctly. Such an in-
vestigation should include a determination of the basic laws of visual
orientation.
An important objective of research is to obtain scientific criteria
for selecting flight personnel. Efforts here have been focused on de-
fining the functional state of the visual analyzer in keeping with the
requirements of flight activity. More precise information is now avail-
able on the requirements for color and spatial vision and a new method
has been devised to test it.
Owing to the extremely heavy load placed on the eyes of the pilot
and the high speeds at which modern airplanes fly, the present methods
of studying isolated visual functions under static conditions, as is
usually done for ease of investigation, are unsatisfactory. Visual
functions must be studied dynamically, with the time factor a major
criterion. This approach will soon become basic in the development of
scientifically sound medical examinations. It will entail research on the
capacity of the visual analyzer, the maximum amount of information that
can be processed in a unit of time, the degree of change in the volume of
information that can be processed while other analyzers are functioning,
51
etc. It will require the joint efforts of physiologists, biophysicists,
and mathematicians and it will help to solve a number of problems in
aviation and space medicine relating to simplification of vehicle control
systems and orientation during flight.
At the dawn of the aviation era the limits of human activity were
determined by the influence of the physical or dynamic factor of flight
and the ability to withstand it. Now, however, technology has developed
to such a point that the limits of human efficiency will depend mainly
on the physical capabilities of man, especially on the capacity of his
analyzers, the study of which should occupy an important place in aviation
and space medicine.
We should like to emphasize, in conclusion, that while there are
several major directions in which the science of aviation and space
medicine should proceed, the specific subjects of investigation should
be connected with the practical problems raised by the development of
aircraft and space vehicles.
THRESHOLD CONTRASTS AND BRIGHTNESS TO ENSURE VISIBILITY
OF OBJECTS AT NIGHT AND DURING THE DAY
V. V. Baranovskiy, L. N. Meyer and V. V. Preobrazhenskiy
One of the characteristics of the visual analyzer which determine
the visibility of objects is contrast sensitivity. The threshold of
contrast sensitivity, i.e., the capacity of the eye to perceive minimum
differences in the brightness of objects and the background, depends on
a number of factors—brightness, angular dimensions and shape of objects,
brightness of surrounding background, and time of presentation of the
objects.
Published data on determining threshold contrasts cannot be fully
utilized for practical calculations because they were based on a small
number of observers and did not take into account the time the objects
under study were presented. We therefore undertook laboratory and field
investigations of threshold contrasts and brightness in relation to the
time of presentation of objects under nighttime and daytime conditions.
The investigations under daytime conditions with illumination of
10,000 lux were started with measurements of the visibility (v) of
black and white disks (from 2 to 25 angular minutes in size) 50 m away
from the observer. The unknown contrast (E) was defined as the ratio
52
of the actual contrast (K) to the visibility (V) : E = - . The contrast
K for dark objects observed on a background of sky against the sun was
taken as 1, but for light objects it was calculated from measurements
B - B
of the brightness of the object (B n ) and sky (B ): K = s .
B o
Seventy observers with a visual acuity of at least 1 took part in
the investigations. Each observer, after a short training period, de-
termined the visibility of objects as they appeared and disappeared in
the visual field.
Threshold values for the conditions under which the objects became
visible or invisible were derived by statistical processing of the ex-
perimental data. The threshold contrast during the appearance of an
object more than 20 angular minutes in size was 0.06 with a probability
of 100 percent. Reduction of the objects to 10, 6, and 2 angular minutes
resulted in an increase in the threshold contrasts to O.lij-, 0.2U, and
O.kh, respectively. The threshold values decreased l-l/2 times for con-
ditions involving the loss of visibility as compared with the appearance
of the objects.
The data can be used for rectangular as well as round objects.
According to the literature, a rectangle with the sides in a ratio of
1:8 cannot be distinguished from an equidimensional disk.
On starry nights, 10 observers in the laboratory determined the
threshold values of the brilliance required for discrimination of sil-
houettes of objects with side ratios of 1:2 and 1:6 during limited and
unlimited periods of time.
The brightness of the background changed from 0.9 to 10" 3 n t. The
size of the background was 1.3 angular degrees; the size of the objects -
6, 10, and 20 angular minutes. The distance between the object and the
observer was 5 m -
The experimental data obtained can be helpful in determining the
maximum brightness beyond which any increase would not hasten discrimi-
nation. Table 1 summarizes the maximum values that ensure almost in-
stantaneous (about 0.0U second) discrimination, with a probability of
100 percent of objects of different angular dimensions with a side
ratio of 1:2 as they appeared against backgrounds of variable brightness.
Analysis of the experimental data shows that the threshold bright-
ness required to discriminate the silhouette of an object grows with
increasing brightness of the background. The smaller the angular dimen-
sion of the object, the greater the brightness that is required to
53
Ta"ble 1. Threshold Brightness Ensuring the Discrimination of
Objects in 0.04 Second Against Backgrounds of Variable
Brightness and Angular Dimensions of Objects with a Side
Ratio of 1:2
Angular dimension
Brightness of
background
(nt)
of object (minutes)
0.93
0.14
0.016
0.01
20
1.6
0.U8
0.10
O.O63
10
2.4
o.8o
0-35
0.25
6
4-3
1.4
0.54
0.40
discriminate it. If the time is increased from 0.04 to 2-5 seconds, the
threshold brightness decreases twofold or more. The intensity of the
threshold brightness derived for objects with a side ratio of 1:2 must
be increased l-l/2 times to permit the discrimination of objects with a
side ratio of 1:6 but with equal width. Moreover, the threshold bright-
ness for the appearance of an object is l-l/2 to 2 times higher than the
threshold brightness when it becomes invisible.
Conclusions
1. The threshold values of contrasts for objects more than 20
angular minutes in size observed against the sky during the daytime are
0.04-0. 06 for the appearance or disappearance of an object, respectively.
2. Virtually instantaneous discrimination of objects at night can
be achieved by doubling the threshold brightness established in the case
of unlimited time of observation.
A NEW METHOD OF STUDYING THE TENDENCY TO ILLUSIONS OF
SPATIAL ORIENTATION
V. V. Baranovskiy and I. D. Semikopnyy
Man orients himself in space as a result of the interaction of sev-
eral analyzers, the visual and vestibular in particular. Thus, the ap-
pearance of illusory sensations of spatial orientation reflects a change
5^
in this interaction. The reasons for the change may stem from the nature
of visual orientation during flight. Systematic tracking movements of
the eye during flights over clouds, in cloudiness of variable density,
when it is raining or snowing, etc., may well be significant. It is
known from the literature (Grable, 1952) that eye movements of fliers
beyond the cabin increase considerably when weather conditions are un-
favorable .
The role of the kinesthetic component in the interaction of the
analyzers has not been adequately studied. Optokinetic nystagmus,
which frequently arises as a reflex of tracking, is a simple and wide-
spread form of visual-kinesthetic association.
In order to assess more objectively the effect of visual-kinesthetic
stimuli on the excitability of the vestibular apparatus, specifically,
on the functional asymmetry of the labyrinth, we determined the degree
to which subjects would turn when walking on a spot with eyes closed
before and after observing moving objects.
The experiments included the following procedures :
(a) Walking on a spot with eyes closed (and wearing opaque eye-
glasses) for 2 minutes.
(b) Observation of moving vertical white-and-black strips 10 cm
wide in a cylinder 80 cm in diameter revolving at the rate of 20 rpm
(angular velocity - 120 deg/sec or 2.l/rad/sec) .
(c) Walking again on a spot with eyes closed for 2 minutes.
While walking the subject took about 100 steps a minute, bending the
legs at the knees and swinging the arms in the usual way. The subject
observed the movement of the white-and-black strips while sitting inside
the cylinder. Meanwhile, we used a mirror to watch the development of
optokinetic nystagmus in the subject as the cylinder was revolving.
The second test of walking on a spot, after observation of the
moving strips, was conducted the same way as at the start of the
experiment. Divisions were placed at every 3O on the floor to record
the degree to which the trunk turned while the subject was walking.
We thus obtained an objective method of investigating the effect
of visual-kinesthetic stimulation on excitability of the vestibular
apparatus, which was reflected in a tendency for illusions to develop and
influence the correctness of spatial orientation.
We also performed a series of experiments involving the observation
of moving objects for 2 to 25 minutes and, in two cases, for 55 and 60
minutes .
55
Before visual-kinesthetic stimulation, 90 percent of the subjects
turned their trunk about 36O while 1 person did so more than 720°.
At the end of the experiment 72 percent made a turn of about 360 , while
10 percent of the persons turned more than 720°.
Analysis of the data revealed an interesting relationship between
the direction of the turning and revolving of the cylinder clockwise and
counterclockwise. For example, in most of the persons (85 out of 108),
the turn after observation of moving objects was in the direction oppo-
site to that of the movement. Consequently, this turn can be regarded
as the result of an illusion of spatial orientation due to visual track-
ing of moving objects. No direct connection was noted between the extent
of the turn at the start of the experiment, before observation of the
moving objects, and that at the end of the experiment.
All this shows the value of using visual-kinesthetic stimulation
in the form of observation of moving objects when investigating the
tendency for an incorrect idea of spatial orientation to arise.
With repeated investigations and a simultaneous increase in the
time of observation of moving objects, the results differed from day to
day, ranging from 30 to 105°.
Of greatest interest, however, are the data obtained after differ-
ent periods of observing moving objects. They show that there is no
direct connection between the time of observation and magnitude of the
turn of the trunk, even in the case of complaints of not feeling well by
the subjects who observed moving objects for 55-60 minutes. They tended
to develop a misconception of their spatial orientation after visual-
kinesthetic stimulation. It arose during the first two minutes and did
not increase even after longer stimulation.
Analysis of the material revealed that the frequency of cases with
a marked reaction of optokinetic nystagmus was virtually the same among
flight personnel and enlisted men.
Study of the data on the flying activities of the pilots who re-
acted sharply to optokinetic stimulation (with a more than 720° turn)
showed that all 6 men were capable of performing their regular flying
duties in accordance with the existing combat training program.
Thus, our method makes it possible to evaluate objectively indi-
vidual idiosyncrasies in impairment of spatial orientation, a subject
that calls for psychophysiological investigation.
56
Conclusions
1. We have developed an objective method of quantitatively deter-
mining individual tendencies toward illusions of spatial orientation
accompanying observation of moving objects.
2. The new method makes it possible to detect about 96 percent of
the persons who develop functional asymmetry of the labyrinth, which re-
sults in a misconception of spatial orientation. This is manifested in
a more than 720° turn of the trunk during 2 minutes of walking on a spot
with closed eyes after optokinetic stimulation.
3. The method can be used in psychophysiological examinations to
select flying personnel for flights in SMU when determining the degree
of fatigue, degree of flight strain, and effect of alcohol intake.
INCREASING RESISTANCE AS A MEANS OF PROVIDING BIOLOGICAL
PROTECTION AGAINST VARIOUS ENVIRONMENTAL FACTORS
DURING FLIGHT
Z . I . Barashova
It is a well-known fact that the means of providing physical pro-
tection for human beings on high-altitude flights and in space travel are
limited. Such factors as vibration, weightlessness, acceleration, and
other overloads can under certain conditions cause pathological changes
in the body. Hence, measures to achieve a high level of general human or
animal resistance remain on the agenda of the day.
By a high level of resistance we mean the capacity of the organism
to function normally under extreme circumstances. If extreme factors
are for short periods of time so strong that the body temporarily is
unable to maintain self-control, then we define as a high level of re-
sistance the capacity of the body to resume normal functioning quickly
and completely, with no impairment of health, as soon as the stressor
ceases to act.
Resistance can be increased in two ways. The single action of some
factor can significantly reduce sensitivity to the effect of the next
adverse factor. For example, moderately severe hypoxia during exposure
to ionizing radiation or the preliminary ingestion of some chemical or
pharmacological substances that prevent peroxides from being stored in
tissues decreases the primary effect of radiation. Similarly, resistance
57
to severe overloads and acute hypoxia can be increased by first injecting
the organism with narcotics or other substances that inhibit the central
nervous system and substantially reduce nerve cell sensitivity to the
above-mentioned factors. However, such biological protection can only be
temporary. It is useless in situations that require man to continue to
function normally while exposed to a stressor.
Of more significance is the increase in resistance that would permit
the normal functioning of all systems, primarily the CNS. This can be
done by specific training (conditioning to the effect of the most in-
jurious agent) and by nonspecific training (increasing the nonspecific
resistance of the body in all possible ways). Nonspecific resistance is
increased by heightening the reactivity of all the homeostatic systems,
especially by changing cell chemistry, which makes the body less vulner-
able to many adverse external and internal environmental factors .
What means can be used to increase general nonspecific resistance,
what are the limits of this nonspecificity, is it possible to change
nonspecific resistance in all living organisms--these are the main prob-
lems that confront us. There is now a mass of information which indi-
cates that directed change in resistance is possible for any organism
from man to Paramecium, even for the plant cell. It is interesting to
note that the means of changing resistance in all kinds of animals are
the same in principle. Such means include the repeated action of agents,
which are addressed ultimately to cell metabolism and which cause adap-
tive changes in cell chemistry. Hypoxia, muscular exertion, change in
ambient temperature, and some drugs can serve as agents. A single expo-
sure by itself can also be a factor in increasing resistance because it
brings about changes both during the action of the agent and after ces-
sation of the action. For example, a one-time exposure to fairly acute
hypoxia or intense muscular exertion (mostly involving high speed) causes
impairment of the oxidation metabolism of cells along with increased
utilization of energy substances (in the case of intense muscular exer-
tion), adaptive increase in activity of the oxidation-reduction enzymes,
intensification of anaerobic release of energy and, as a result, accumu-
lation of incompletely oxidized metabolic products and growth of the
oxygen debt. There is an excessive accumulation of energy sources (gly-
cogen, phosphocreatine), proteins -enzymes, and various biologically active
substances (myoglobin, glutathione, ascorbic acid, creatine, etc.) in the
restoration period. Similar processes take place in a great variety of
tissues.
These trace reactions are gradually extinguished if the same stres-
sors do not continue to act. When repeated, they again bring about the
whole set of biochemical changes in the cells followed by a restoration
phase. The adaptation processes improve and become more economical; they
are summed up and become consolidated, i.e., they persist for longer
periods of time. The resultant adaptation weakens, so to speak, the
58
initial force of the agent because the cells "learn" to react more eco-
nomically and "resourcefully". In other words, the cell structures be-
come more resistant. The changes in cell chemistry are not limited to
changes in the nature and rate of the metabolic processes. There are
other processes with still unknown mechanism that increase the resistance
of cell structures to a great variety of agents that are addressed to
the metabolic processes and at the same time directly influence the native
structure of the cell. For example, rat muscle tissue and cerebrocortical
tissue adapted to hypoxia become more resistant to ethyl alcohol or high
concentrations of caffeine. The sorption properties of reticuloendo-
thelial tissue decrease with respect to vital dyes while the osmotic
resistance of erythrocytes grows . The structural reorganization of
muscle tissue can also be judged from changes in electroconductivity
and dielectric permeability of muscles in vivo. In some way or other
the properties of the structural and contracting proteins of the skele-
tal musculature change. The rate of restoration of the actomyosin com-
plex, after dissociation of this complex by ATP, was found to be higher
in rats adapted to hypoxia than in the control .
Although these fragmentary data do not completely account for the
origin of changes at the cell level in animals adapted to hypoxia, they
undoubtedly do indicate that there are significant changes in the physico-
chemical properties of cells in animals conditioned to hypoxia.
Since repetition of the action of different stressors (hypoxia,
muscular exertion, changes in ambient temperature, some drugs or other
chemical compounds) reveals the existence of similar changes in cell
chemistry, it is easy to understand why conditioning to hypoxia, for
example, increases resistance to chilling or to the performance of high-
speed muscular work, acceleration or radiation, and why muscle condi-
tioning increases resistance to hypoxia, acceleration, chilling, etc.
Cell chemistry changes at all levels following exposure to extreme
factors. Nonspecific resistance increases wherever adaptation to re-
peated exposure to stressors occurs. Consequently, it is fair to say
that adaptive changes at the cell level are the basis of nonspecific
resistance in the organism.
Nevertheless, the concept of nonspecificity is not an absolute one
because each adaptation may include not only common or similar processes
but also specific adaptive reactions which need not have general signifi-
cance. Resemblance in cell adaptation is by no means identity. More-
over, the complex organisms of the higher animals include in their
mechanisms of adaptation not only changes at the cell level but adaptive
changes in the functioning of different systems, the significance of which
may vary from situation to situation.
It is worth noting, too, that not every kind of conditioning will
lead to a change in nonspecific resistance. It is essential to take into
59
account the nature and force of the agent, the frequency and duration of
its use. The facts show that only a rational and many-sided condition-
ing of the human or animal organism ends in increased nonspecific re-
sistance.
RESPIRATION AND GAS EXCHANGE IN AN ACUTE HYPOXIC TEST
A. V. Beregovkin, P. V. Buyanov and V. B. Malkin
Hypoxic hypoxia is now widely used as a functional test of nervous
reserves, respiration, and blood circulation in essentially healthy
persons and as a means of detecting various latent forms of disease.
There is a definite correlation between resistance to oxygen deficiency
and resistance to other unfavorable environmental factors (high and low
temperature, hypocapnia, radiation, etc.).
The use of hypoxic hypoxia as a functional test is a promising
method of selecting flight personnel and of keeping under dynamic ob-
servation persons exposed to a variety of flight factors. Accordingly,
we undertook an investigation of respiratory function and gas exchange in
hypoxic hypoxia. The purpose of our work was both to determine the gen-
eral principles underlying changes in respiration and to detect indi-
vidual respiratory reactions to hypoxia. We also endeavored to evaluate
the individual reactions from the diagnostic standpoint.
Acute hypoxic hypoxia was caused by inhalation of gaseous mixtures
of nitrogen with oxygen. There was a total of 6k investigations involv-
ing U8 essentially healthy males ranging in age from 20 to 23 years. In
the first series of investigations, we used a mixture with an oxygen
content of 9-3-10.9 percent; in the second series, the oxygen content
was 8-8.5 percent.
The investigations were conducted under the conditions of basal
metabolism (immediately after a night's sleep, on an empty stomach,
lying down). The frequency, depth, and rhythm of respiratory movements
and the maximum lung capacity were recorded with a spirograph. Pul-
monary ventilation was determined with a gas meter. The Douglas -Haldane
method was used to investigate gas exchange.
The principal indices of respiration and gas exchange were deter-
mined at rest, during breathing of the gaseous mixture, and after chang-
ing to breathing of atmospheric air.
60
Analysis of the results show that pulmonary ventilation, depth of
respiration, maximum lung capacity, and oxygen consumption were defi-
nitely related to the degree to which the partial pressure of oxygen was
reduced in the inhaled mixture.
Pulmonary ventilation increased in 5^- cases (by 3-125 percent), re-
mained unchanged in 3, and decreased in 6 (3-3O percent).
In the first series of investigations, pulmonary ventilation in-
creased on the average by 2k percent, in the second series, by h'J per-
cent.
The respiration rate scarcely changed. Average figures for the
change in respiration rate remained within the limits of errors in the
method .
The depth of respiratory movements increased in 58 cases (by 8-
I76 percent), remained unchanged in h, and decreased in 2 (by 8-21 per-
cent) .
In the first series of investigations, the vital capacity increased
on the average by 28 percent, in the second series, by 51 percent. Pul-
monary ventilation increased mostly through an increase in the depth of
respiration.
The maximum capacity of the lungs decreased in k-9 investigations
(by U-65 percent), remained unchange in 2, increased by 6 percent in 1.
In the first series of investigations, the maximum lung capacity
decreased on the average by 16 percent, in the second series, by 28
percent .
Similar changes in external respiration were noted under the con-
ditions of rarefied atmosphere with elevations in the pressure chamber
to "altitudes" of 5OOO-7OOO m.
Oxygen consumption in the first series of investigations decreased
after 15 minutes by an average of 11 percent and then gradually increased
until the end of the test (50th minute) when it was 98 percent of the
original level, i.e., this index returned to normal.
The amount of oxygen consumed in the second series dropped by 71
percent (U-6 minutes) and by the end of the investigation was only 79
percent (15 minutes).
During the first few minutes (h-6) after breathing atmospheric air,
oxygen consumption was higher than the original figures (by h-0 percent
in the second series).
61
The diagnostic significance of the degree of increase in pulmonary
ventilation is of considerable value in determining the individual re-
sistance of healthy persons to hypoxia. There are two schools of thought
on this matter. Most authors associate a high level of ventilation with
good resistance to oxygen deficiency (A. P. Apollonov, V. G. Mirolyubov,
P. K. Isakov, L. L. Shik, and others). Others attach considerable sig-
nificance to hypocapnia as a factor that largely determines individual
resistance to hypoxic hypoxia (V. V. Strel'tsov, Antony, and others).
In our investigations, a decrease in pulmonary ventilation, like
an extreme increase (more than 100 percent above the original level)
was generally associated with poor tolerance of hypoxia.
Evidently both of the aforementioned points of view are rather
one-sided. A low level of ventilation results in severe hypoxic dis-
orders, whereas a marked increase (over 100 percent) lowers resistance
to oxygen deficiency due to the development of hypocapnia. Thus,
there seems to be an optimum area of increase in pulmonary ventilation
which varies with the extent to which the partial pressure of oxygen in
inhaled air is reduced and with the individual characteristics of the
person examined (specifically, his sensitivity to hypocapnia). For
most persons this area with gaseous mixtures containing 10.5 percent
oxygen ranges from 20 to 75 percent, 8 percent oxygen - from 30 to 90
percent.
There is no consensus in the literature on the nature of the reflex
reorganization of respiration. Several investigators state that an
accelerated respiration rate in hypoxic hypoxia is the most typical
feature of external respiration, whereas changes in the depth of res-
piratory movements are more variable (Haldane and Priestley, 1937; A. G.
Ginitsinskiy and A. V. Lebedinskiy, I9V7). P. I. Yegorov (1932) noted,
however, that with the development of acute oxygen deficiency essentially
healthy persons have slightly more numerous respiratory movements (an
increase of 10 percent), but respiration becomes quite deep.
In our observations, the increase in pulmonary ventilation was oc-
casioned mainly by increased vital capacity. Unchanged vital capacity
or a decrease therein testified to low resistance to hypoxia.
Thus, increased depth of respiration is the most typical form of
human adaptation reaction to insufficient oxygen in inhaled air. (A
reduction in maximum lung capacity in hypoxic hypoxia is mentioned by
Paul Behr . )
We found no references in the literature to the diagnostic value
of this index in hypoxia. The reduction in maximum capacity noted in
most of our observations was evidently due to hypervolemia of the pul-
monary circulation and thus the result of a compensatory reaction to the
62
extensive aeration of blood in the lungs. However, a marked decrease in
vital capacity (by UO percent or more) generally coincided with poor
performance in the hypoxic test. This last was probably caused by
severe impairment of the hemodynamics of the pulmonary circulation. This
assumption is based on the results of investigations in which the de-
velopment of hypoxic hypoxia was associated with a substantial increase
in pressure in the right ventricle of the heart and pulmonary artery
(V. V. Parin and F. Z. Meyerson, others).
The changes that we noted in oxygen consumption in acute oxygen
deficiency confirm the results of studies by L. L. Shik, Ye. Opitts,
and others, who observed during the first minutes of the onset of
hypoxia a decrease in oxygen consumption followed by an increase and
then a return close to the original level. A pronounced decrease in
oxygen consumption during the first minutes of an investigation and its
slow restoration are an index of low resistance to oxygen deficiency.
Thus, the diagnostic criteria of low resistance to oxygen deficiency
were the absence of an appreciable change in the volume of pulmonary
ventilation or a sharp increase therein (over 100 percent), a decrease
in the depth of respiration, a marked decrease in vital capacity (k-0
percent or more), and a marked reduction of gas exchange early in the
test followed by a slow return to normal .
EFFECT OF CHANGE IN THE GAS MEDIUM ON "PRIMARY POTENTIALS"
OF THE AUDITORY AREA OF THE CEREBRAL CORTEX IN ANIMALS
AND ON SOME FUNCTIONS OF THE ACOUSTIC ANALYZER IN MAN
E. V. Bondarev
The present stage in aviation technology requires a deeper and more
comprehensive investigation of the adverse factors encountered in flight
(acceleration, hypoxia, noise, etc.). Of equal importance is a problem
in space research pertaining to living quarters on space vehicles, namely,
the composition of the artificial gas medium in a hermetically sealed
capsule .
Interest in the acoustic analyzer of fliers on jet aircraft is grow-
ing because of its heavy load. The possibility of substituting sound
signals for some of the visual information is now under discussion.
We studied the effect of flight factors on the acoustic analyzer in
two respects: (a) the influence of hypoxia and substitution of helium
63
for nitrogen in the ambient atmosphere on the "primary potentials" of
the auditory area of the cerebral cortex in response to sound; (b) the
influence of moderate hypoxia (corresponding to an altitude of 5000 m)
on some functions of the human acoustic analyzer.
Changes in the "primary potentials" were investigated in a chronic
experiment using "f cats with electrodes implanted in the auditory region
of the cortex. During the investigation the animal was kept in a her-
metically sealed chamber secured to a special bench in such a way as to
enable it to maintain its normal posture. The "primary potentials"
were evoked by brief (80 m/sec) sounding of pure tones at frequencies
of 500, 1000, 3000, 6000, and 10,000 cps from an audio oscillator with
a constant intensity of 60 db at the level of the animal's ear. The
tones were supplied at the rate of 5-7 per minute through a high-
fidelity loud speaker.
We began by recording the "primary responses" of the auditory area
of the cortex to the sounds with the animals breathing the surrounding
air (control). Some of the animals were then elevated in the pressure
chamber to "altitudes" of 5000 and 8000 m (from the platform in 30
minutes). In other cases the chamber was successively filled with
gaseous mixtures containing 11.2, 7-2, and 6.8 percent oxygen, corre-
sponding to altitudes of 5000, 8000, and 9000 m (from the platform in
30 minutes). In still other cases the atmospheric nitrogen was almost
completely replaced with helium at a normal barometric pressure; the
animals were kept in this mixture for 12 hours.
The following served as indices of the "primary response": latent
period of the reaction calculated from the time the stimulus was applied,
the inter pity and duration of the positive and succeeding negative
phases of the induced potentials, and the amplitude ratio in both phases.
The second part of the investigation was carried out on 20 subjects,
18-28 years of age, in a pressure chamber at an "altitude" of 5000 m.
The following indexes of the condition of the acoustic analyzer were in-
vestigated: intelligibility of the words presented to the subjects with
different degrees of intensity; operating efficiency according to the
data of a sampling reaction, and interval of discreteness of separate
perception of two sound stimuli.
The intelligibility of words was determined from articulation
tables prepared on the basis of recent research on the physical and
phonetic constants of Russian speech. The differences in intensity
levels of the tests made it possible to obtain a speech audiogram.
The operating efficiency of the acoustic analyzer was determined
in a sampling reaction from Shannon's formula, taking into account the
number of correct responses, errors, and reaction time. The interval of
6h
discreteness was determined from the differentiation of single and double
clicks .
After statistically processing the results of the investigations,
we found that :
(a) Changes in the "primary potentials" of the auditory area of the
cat cortex began to appear at an "altitude" of 5000 m and became more
pronounced at 8000-9000 m.
(b) With hypoxia there was a lengthening of the latent period of
the "primary potentials", a progressive decrease in the amplitude of
the negative phase, and, starting at 8000 m, increase in and shortening
of the positive phase; the responses to the higher frequency sounds
(above 6000 cps) were more affected.
(c) Twelve hours of exposure to a helium-oxygen mixture had no
significant effect on the "primary potentials" of the auditory area of
the cat cortex.
(d) Moderate hypoxia at an "altitude" of 5000 m raised the threshold
of perception of sound in the healthy subjects but somewhat reduced the
intelligibility of words at low sound intensities; when the subjects
were conditioned to "altitude", the above-mentioned changes were less
pronounced.
(e) The operating efficiency and interval of discreteness of the
acoustic analyzer showed no significant changes at an "altitude" of
5000 m.
THE POSSIBILITY OF BIOLOGICAL OBJECTS GROWING AND LIVING
A LONG TIME IN A HELIUM- OXYGEN ATMOSPHERE
V. V. Boriskin, P. A. Gul'tyayev and B. M. Savin
One of the most important problems relating to living quarters on
spacecraft designed for distant travel is the creation and maintenance
of the most suitable gas medium. It requires the creation of highly
favorable conditions for biological objects to grow normally and sur-
vive on long flights, and the ability to provide the necessary equip-
ment.
saaj
65
The great interest displayed in recent years in studying the effect
of substituting helium for nitrogen in the ambient atmosphere on animals
and human beings is due to the fact that helium, as an inert gas, is
superior in several respects to nitrogen as a diluent of oxygen in the
cabins of interplanetary spaceships.
The possibility of living things growing and living for a long
period in a helium-oxygen atmosphere is also highly interesting from
the standpoint of general biology because it may help to determine the
biological significance of atmospheric nitrogen for the higher animals
and man. The literature on the subject is meager and contradictory.
These problems were studied in I96O-I96I in a series of experi-
ments involving a variety of biological objects in different stages of
ontogenetic and philogenetic development, and kept for many days in a
helium-oxygen atmosphere. We investigated the possibility of (a)
chick embryos and frog egg cells developing in a helium-oxygen atmos-
phere, and (b) of chicks, white mice, and dogs living in this atmos-
phere for 10-15 days. For the purpose of comparison, parallel experi-
ments were performed with the same biological objects in a nitrogen-
oxygen atmosphere.
The oxygen content of both gas media ranged from 19-2 3 percent, the
COg content, from 0.2-1.2 percent. The amount of nitrogen present did
not exceed 1-1. 5 percent.
Results
Development of chick embryos. Inspection and weighing of the eggs
and examination of the embryos extracted from them at different stages
of development failed to reveal any significant differences- -either in
time or in nature of embryogenesis--between the egg cells incubated for
21 days in the helium-oxygen and nitrogen-oxygen media. It was noted,
however, that shrinkage of the eggs during incubation was 3-5 percent
greater and the weight of the hatched chicks was 2 g lighter in the
helium-oxygen atmosphere than in the nitrogen-oxygen. It was impos-
sible to determine whether this was due to the higher temperature at
which the helium-oxygen medium was maintained or to the physicochemical
properties of the helium.
With maintenance of the incubation temperature conditions, approxi-
mately the same number of chicks was hatched in both gas media. Con-
tinued observation of their growth and development until maturity under
ordinary conditions failed to reveal any significant difference between
them.
66
Development of frog egg cells. Observation of the development of
frog eggs in the gas media under study was particularly interesting be-
cause it took place in water, which possesses higher thermal conductiv-
ity than helium. This leveled out the difference between nitrogen and
helium with respect to their influence on heat loss. Frog development is
attended by several complex phases of reorganization and transformation
during which the exclusion of atmospheric nitrogen apparently cannot
help but have an effect if its presence is actually necessary for normal
development. However, 20 days of observation of the embryonal and larval
periods of development in the medium in which atmospheric nitrogen was
replaced by helium failed to reveal anything unusual either in the time
they occurred or in their nature. Nor were any differences noted between
the experimental and control groups when the tadpoles were shifted from
the helium-oxygen medium to ordinary atmospheric conditions and observed
for 2 months as they passed through all the stages of metamorphosis and
formation of the frog organism.
Chicks and White Mice Kept in a Helium-Oxygen Medium
Two groups of chicks incubated in nitrogen-oxygen and helium-oxygen
media were placed in a chamber with a helium-oxygen atmosphere as soon
as they were hatched. Ten days' observation of their growth, weight,
general behavior, and reaction to food and various external stimuli
showed that with an outside temperature of about 30°C, which is essential
to maintain the thermal balance and normal behavior of chicks in an or-
dinary atmosphere, the chicks in the helium- oxygen medium "froze",
bunched together, moved about, and ate very little. Raising the tempera-
ture of the helium-oxygen medium to 3U-36 resulted in normalization of
motor and feeding activity, and the subsequent development and behavior
of the chicks were the same as in an ordinary atmosphere. After they
were transferred to ordinary living conditions, they reached maturity
without exhibiting any adverse effects from the 10 days they were kept
in the helium-oxygen medium.
The results were the same in the experiments with the mice, which
were kept for 15 days in a helium- oxygen medium. The mice showed no
signs of temperature discomfort in the nitrogen-oxygen medium when the
ambient temperature was 21-22° or in the helium-oxygen medium when the
temperature was 2^-25°. With these temperature regimes there were no
perceptible differences in the condition and behavior of the animals in
the two gas media. Nor were any adverse effects observed after they were
transferred to ordinary living conditions.
Dogs Kept in a Helium-Oxygen Medium
Dogs were kept in a helium-oxygen medium for Ik days, during which
we observed their behavior, external respiration, gas exchange, energy
67
consumption., electrocardiogram, conditioned reflexes, skin, subcutaneous,
muscular, and rectal temperatures. We found that with an external tem-
perature of 23-26 muscular and subcutaneous temperatures dropped by
O.7-O.9 , energy consumption increased by 80 m/kal per minute, and the
cardiac rate accelerated by 10 beats per minute . There was a diminution
of motor and feeding activity, and some inhibition of conditioned re-
flexes. Raising the external temperature to 27-28° brought the tempera-
ture of body tissues and physiological functions to their original level
and under these conditions these indices did not differ from those of the
animals kept in the nitrogen-oxygen atmosphere at an ambient temperature
of 19. 5-22. 5°. The animals' motor activity was also restored. Subsequent
observation of the animals under ordinary conditions disclosed no adverse
effects from the many days they spent in the helium-oxygen medium.
Thus, our experiments show that substituting helium for oxygen in
the ambient atmosphere had no appreciable effect on embryonal develop-
ment. When a higher ambient temperature was maintained in order to pre-
serve the thermal balance, long exposure to the helium-oxygen atmosphere
did not impair the vitality of animals representing different stages of
phylogenetic development. The need to maintain a higher temperature
(by 14.-6°) in the helium-oxygen atmosphere was occasioned by the fact that
helium has greater thermal conductivity than nitrogen and thus causes the
organism to emit more heat.
SOME ASPECTS OF MEDICAL EXAMINATION OF FLIGHT PERSONNEL
K. F. Borodin
1. Medical examination of flight personnel (MEFP) in Russia has
come a long way since the War Department issued its first order defining
the medical requirements in selecting personnel for balloon and air units.
This important branch of medicine has developed chiefly in the direction
of matching the health requirements of personnel with flying conditions
on different kinds of aircraft and perfecting appropriate examination
methods .
Instead of a priori requirements for visual acuity, color perception,
condition of the labyrinth, and physical development- -to which the orders
of prerevolutionary Russia were largely restricted- -we now have a docu-
ment that deals both with matters concerning the organization of exami-
nations and with scientifically valid, differentiated health requirements
for members of crews on different kinds of planes. We have also a spe-
cial handbook for medical commissions describing the procedures used in
MEFP.
68
2. The theory of flight fitness examinations rests on a scientific
and materialistic understanding of the unity and interdependence of so-
matic and mental processes, of social and biological factors, of the
human organism and the environment.
The main principles of MEFP include :
(a) Comprehensive study of the individual, including a general
physical examination, special physiological, psychological, and other
functional investigations resembling flight conditions and study of the
individual under actual flying conditions.
(b) Continuous evaluation of the health of flight personnel through
periodical medical examinations, preflight medical check-ups, and keeping
of records.
(c) A scientifically grounded and MEFP-approved individualized
method of evaluating the results of investigations from the biological
as well as social standpoints. The fitness for flying of individuals
with health abnormalities is determined on the basis of formal symptoms
of disease and with due regard for the functional capabilities of the
individual, stage of disease, prognosis of occupational activity, atti-
tude, value to the service, experience, etc.
3. Despite the success of MEFP, some matters call for further
study. One need is to improve and secure wider use of functional methods
of investigation that reflect more accurately activities on various kinds
of aircraft in order to determine the fitness of examinees. This is
necessary because the possibility of continuing flight activities is not
always determined by morphological changes, that is to say, the functional
state of the organism very often establishes the framework of the occu-
pational activity of flight personnel. The problem should be dealt with
in practice chiefly by :
(a) Making wider use of certain excellent clinical methods of func-
tional investigation on an outpatient and, especially, inpatient basis.
(b) Administering a specially prepared program of tests in flight
so as to determine the effect of existing health conditions on efficiency.
(c) Undertaking scientific research to find and check new functional
tests.
The various approved methods of investigation and evaluation of the
results are fully described in official handbooks. We need only empha-
size that the recommended number of investigations should be made in
every single case.
69
Tests during flights should assume increasing importance. Specifi-
cally, they should be considered mandatory for vestibular disorders,
marked decrease in auditory acuity, persistent impairment of the baro-
f unction of the ears and appendages of the paranasal sinuses. The tests
should be given with due regard for flight safety and, of course, in the
absence of contraindications.
h. There are two trends in the research aimed at finding new
methods of investigation that are more in line with flying conditions.
One is to determine the functional capabilities of the individual with
respect to concrete flying conditions. The other is to detect incipi-
ent forms of diseases and latent functional impairments.
Included in the first trend are :
(a) Establishment of criteria for evaluating the functional capacity
of the cardiovascular and respiratory systems for tolerance of respira-
tion at an excess pressure.
(b) Establishment of criteria for expert evaluation of the results
of tests on a flight trainer.
(c) Refinement of speech audiometry data to deal with the problem
of audibility of radio signals during flight.
(d) Development of better methods of determining the physical con-
dition of flight personnel in order to judge their ability to withstand
unfavorable flight factors .
(e) Dynamic investigation of visual analyzer function in order to
determine the rate of visual perception under flight conditions.
This trend is concerned with investigating the functional capabili-
ties both of individual analyzers and systems and of the body as a whole
for tolerating the specific conditions of flight activities.
The second trend of research assumes that the onset of diseases
that limit or make impossible flight activities is usually preceded by
functional, often reversible, changes in the body, although these changes
cannot be readily detected in the ordinary physical examination, they
must be known before it is decided whether the examinees should be per-
mitted to continue flying and whether corrective measures are feasible.
Of greatest practical importance is determining the initial mani-
festations of atherosclerosis of the coronary blood vessels. The
methods now used (EKG investigation with inhalation of an oxygen-poor
gas mixture, after injection of glucose; pressure -chamber tests; deter-
mination of the rate of blood flow, etc.) are sometimes helpful in turning
70
up latent forms of the disease, but we are not completely satisfied
with the data they yield.
It is equally important to find ways of detecting the initial mani-
festations of sclerosis of the cerebral arteries. The clinical data
obtained in the course of the usual neurological investigation are usually
indicative of an advanced stage of the disease and they are rarely en-
countered by medical commissions. The psychological tests used for this
purpose likewise do not provide a complete answer. It is important
that physiological and psychological tests be designed which would
permit early diagnosis of incipient sclerosis of the cerebral arteries,
when there are only slight abnormalities in CWS function.
5. Research efforts must be directed toward achieving maximum
objectivization of examination results. It is wrong, however, to try
to set up precise criteria, as some investigators do, for determining
the degree of fitness for flying from the results of a given investiga-
tion. Each investigation should be considered simply as one part of
the clinical examination which is designed to help in making an accurate
diagnosis or to evaluate certain specific functional capabilities. One
investigation is a completely inadequate basis for an expert decision;
this is reached only in the course of a collective discussion of all
examination results and evaluation of a host of other factors, particu-
larly, compensation of an existing health defect, nature of future flight
assignment, and many others. Therefore, the results of various in-
vestigations should make possible a more objective evaluation of the
functioning of a given organ ( system) or tolerance of individual flight
factors or certain adverse environmental conditions, but not a determi-
nation of the degree of fitness for flying.
OBESITY IN FLIERS
I. M. Buznik
Obesity is not uncommon among fliers. It usually develops in
older, generally highly competent, persons. Obesity reduces resistance
to overloads, increases sensitivity to decompression disorders (Arm-
strong, I95U), and decreases physical endurance. All this naturally has
an adverse effect on the fitness and combat efficiency of the individual,
and also impairs flight safety. We concluded from an analysis of the re-
sults of weighing fliers that the number of those for whom obesity pre-
ventive and therapeutic measures should be taken is very substantial.
71
It is widely believed that obesity is caused by overeating. But
this is scarcely enough to explain the pathogenesis of obesity or to
provide the basis of preventive and therapeutic measures. After all,
any obesity results from overeating, i.e., from the consumption of more
food than the body needs .
Obesity in fliers is often said to be due to the high caloric con-
tent of their food ration. Reduce the ration, then, and you will pre-
vent obesity. But if this were so, how does it happen that all fliers
do not get fat? Why is the weight of some fliers abnormally low? The
reason is evidently not to be sought solely in excess caloric intake.
In studying the problem, we analyzed the weight of fliers over a
period of years, tracing the pattern of weight gain in those suffering
from obesity. Weight is put on slowly and it becomes pronounced only
after a few years. The average increase is 1-2 kg a year, rarely 3-U
kg. It may be due to a very slight excess in the caloric content of the
food eaten over the amount of energy expended, which can easily be
demonstrated by appropriate calculations. For example, if the weight
gain for a year is 3.65 kg, it will average about 10 g per day. This is
equal to a daily excess of 7-8 g of food fat or 70-80 calories of other
nutrients. Consequently, the excess of calories in food over the amount
of energy expended need be very slight for obesity to develop.
In the light of the foregoing, it is doubtful that obesity can be
successfully controlled by reducing the caloric content of the fliers '
ration, say, to U000 kcal because on some days they would exceed the
energy expended. For example, in expending about 3000 kcal or energy,
the excess will come to 1000 kcal. To reduce the caloric content even
more is hardly feasible because the energy expenditure of fliers varies
within fairly broad limits from day to day and it may amount to U000
kcal (0. P. Molchanova, A. F. Legun). On such days a ration with a
small caloric content would clearly be inadequate.
It is difficult to say whether excessive calories in the diet is
the cause or only a precondition of obesity. It is a generally known
fact, confirmed by special investigations, that in healthy young people
the energy balance is regulated by quite accurately determined physio-
logical mechanisms. Such persons do not become corpulent regardless of
the amount of food they eat (i. M. Buznik, 195l). Hence, obesity de-
velops not because of the food eaten but because for some reason regula-
tion of its utilization has been impaired. The reason is to be found
in metabolic impairment which makes overeating possible. If this is so,
reducing the caloric content of the ration will not by itself overcome
obesity unless, of course, the ration is clearly inadequate.
For greater clarity and exposure of the dynamics, the results of weigh-
ing will be represented graphically.
72
The connection between metabolic impairment and obesity is some-
times obvious, as in endocrine disorders. The more frequent development
of obesity in older persons can also be linked to a change in metabolism.
Age increases the activity of the diencephalic-hypophyseal system, which
is involved in regulating lipid metabolism, endocrine and liver function,
etc. Neuroses, obesity, and other metabolic disorders arise as a result.
Obesity is often attributed to inadequate physical activity. The
relationship between the latter and amount of energy expended is beyond
doubt. The greater the physical exertion, the more energy is expended
and the less opportunity for excess depositon of fat. However, even
here is it more difficult to prove a causal relationship than appears
at first sight. It is not quite clear why, for example, slight physical
activity contributes to the development of obesity in some persons,
whereas it has no effect on the weight of others .
The psychological factor, including the attitude to food, although
usually underestimated, is of considerable importance. Unnecessary
stimulation of the appetite with alcoholic drinks and spicy food and
poor family habits with respect to overeating also promote obesity.
Hereditary predisposition may be another factor.
Thus, the main reason for obesity is impaired regulation of metab-
olism. An excess food intake and slight physical activity are factors
in the development of obesity but not the causes. Autonomic -endocrine
disorders, hereditary predisposition, and the psychological factor may
also play a role in the process. The extent to which metabolic dis-
orders may be caused by flying is not clear.
It is extremely difficult to cure obesity. What are required are
easily applied methods and instructions that will not be left on the
paper on which they are written. It is sometimes recommended that a
special menu be prepared for fat people, noting the amount of food con-
sumed and the chemical composition. But this would require special per-
sonnel and it would not be of much value because calculations of the
caloric content of a diet will mean very little unless the amount of
energy expended is known. Only a rough guess can be made as to the energy
likely to be expended in a given physical activity. For this reason we
think it is fundamentally impossible artificially to regulate the energy
balance. The fact is we can only reduce the caloric content of a diet
and bring it to a point where it will cause partial starvation and a
lowering of efficiency.
Most methods of weight reduction are unfortunately linked to sharp
limitations on food intake (M. N. Yegorov and L. M. Prostyakov, 1957;
Tanhauser, 193^; Norden, 1930; Banting and Epstein, 1887; others). Such
methods are impracticable in a flying unit because a marked limitation
of caloric content might result in weakness, ready fatigability, and
sharp impairment of efficiency.
m.
73
Experience has also shown that the results of such treatment are
not permanent, for the weight lost Is regained fairly quickly. The
reason for this, we believe, is the crudeness of the methods based on
dietary restrictions. Sharp limitations on food intake cause powerful,
adequate stimulation of the receptors that regulate the energy balance.
The result is appetite stimulation and a change in attitude toward food
and treatment .
Study of the pathogenesis of obesity suggests another approach.
Obesity should be eliminated as slowly and as imperceptibly as it de-
velops. This requires rather minor dietary restrictions. A slight
reduction in the portion to be eaten will sometimes be effective. By
regulating the intake of food and observing his weight, every obese
person can stabilize and then reduce it. It must be borne in mind that
without the active cooperation of the individual, nothing will succeed.
Even if his food intake is restricted, the weight may remain unaltered
because a fa I person can decrease the expenditure of energy by reducing
his physical activity.
Increased physical exertion could well play an important part in the
prevention and treatment of obesity. Physical exercise, sports, hiking,
tourism, and hunting are other useful ways of normalizing the energy
balance. They confer the additional benefit of increasing the functional
capacity of the body, especially that of the cardiovascular system.
FUNCTIONAL EVALUATION OF BLOOD CIRCULATION FROM CHANGE IN
CIRCULATION EFFECTIVENESS. VALUE OF THE METHOD IN
SELECTING AND TRAINING FLYING PERSONNEL
P. V. Buyanov
Methods of functional evaluation of blood circulation are essential
for the selection, preparation, and training of flying personnel. They
are useful in studying the compensatory-adaptive capabilities of the
body in response to flight factors. Supervision of the course of train-
ing and prevention of damage to the adaptive mechanisms are particularly
important .
The method of recording tacho-oscillograms and oscillograms makes
it possible to judge the functional adequacy of blood circulation from
the condition of the main indices of hemodynamics, each of which throws
light on a particular phase of hemodynamics. Only the minute volume of
circulating blood can characterize cardiovascular function. However,
7k
the absolute values of the minute volume • have no independent meaning con-
sidered apart from gas exchange because cardiac activity is directed
wholly at providing the body with the nutrients it requires, chiefly
oxygen, in adequate quantities and at the right time. The relationship
between the metabolic processes and cardiac output has long been known
(Linhard, 1915; Lundsgaad, 1915 ; Ewig, 1931; Bauman and Grolman, 19 3I;
N. N. Savitskiy, 1935; others). Thus, the minute volume can give us an
idea of the functional sufficiency of blood circulation only when cor-
related with the metabolic processes. Savitskiy was quite justified in
introducing the concept of an obligate (proper) minute volume needed
for normal oxidation under the conditions of basal metabolism. Later
studies demonstrated the practical value of the concept of "obligate
minute volume" in functional diagnosis of the blood circulation in
various pathological processes (S. 0. Vul'fovich, 1935; B. A. Ivanovskiy,
1935; V. P. Nikitin, 1950; P. V. Buyanov, 1958; others).
The method of evaluating the obligate volume has two main short-
comings . First, the volume is calculated from tables of the proper
basal metabolism; the actual gas exchange characteristic of a given
subject under certain conditions is not taken into account. Second,
it does not permit a comparison to be made of the cardiovascular
system after measured loads. In aviation, space, and sports medicine
practice, the functional adequacy of the cardiovascular system is de-
termined chiefly from its reaction to load tests and tolerance of occu-
pational factors .
In I958-I963 we conducted investigations in which we simultaneously
studied oxygen utilization and cardiac output both under the conditions
of complete physical rest and after various actions (measured physical
exercise, breathing at a high pressure, oxygen deficiency, influence of
hypodynamia). Thirty deep squats a minute served as the test involving
measured physical exercise. Breathing at a high pressure ( 3OO mm HpO)
continued for 10 minutes. Gas mixtures with an oxygen content of 8.0-
8.5 percent (duration of respiration 10-15 minutes) and 9- 3-10-5 percent
(duration 3O-60 minutes) were used in the oxygen deficiency test.
The hemodynamic indices were determined from tacho-oscillograms
and oscillograms recorded on a mechanocardiograph designed by N. N.
Savitskiy. The cardiac output was found graphically by Bremzer and
Tanke's method as modified by Liliestrand and W. N. Savitskiy, oxygen
utilization - by Haldane's method (2U5 observations) and Belau's method
(101 observations).
Since the cardiac output is a function of gas exchange and the
functional adequacy of the cardiovascular system is proportional to the
economy with which the volume of circulating blood is used with an equal
amount of utilized oxygen, we introduced an index of blood circulation
effectiveness. This index is determined from the volume of blood used
75
per 100 m3 of oxygen utilized by the body. The less blood used per unit
of oxygen utilized, the more effective blood circulation is.
A total of 3U6 investigations were conducted under the conditions
of complete physical rest. The index of circulation effectiveness
averaged 2.0^ liters (between 1.60 and 2.M3). In most cases, the values
of the index were similar in repeated investigations of the same person.
In our opinion, the index indicates the degree of efficiency of
cardiovascular regulation with respect to gas exchange. Despite syste-
matic exposure of the men to different aviation factors within the limits
of their endurance, the index of circulation effectiveness either did not
change or it even dropped appreciably. The latter was apparently caused
by the development of compensatory-adaptive reactions and indicates that
the men were well trained to cope with these factors. In some of the
subjects, systematic exposure to high pressure, high temperatures, and
prolonged restriction of movements substantially increased the volume of
circulating blood needed for the body to use the given amount of oxygen.
The latter indicates that the influence of the above-mentioned factors
was beyond the compensatory capabilities of the body. Cessation of the
actions and establishment of a suitable regime generally caused a return
of the index of blood circulation effectiveness to normal.
Blood circulation effectiveness was low in some of the subjects.
As a rule, they had a large volume of blood in relation to the oxygen
utilized. These persons had little endurance and ability to adapt to
various aviation factors. Some of them eventually suffered impairment
of the cardiac rhythm and had hypertensive reactions.
The effectiveness of the blood flow increased after measured physical
exercise. The index of blood circulation effectiveness in the healthy
persons ranged from O.78 to 1.22 liters (l.OO on the average). Five
minutes after the exercise it rose in most instances to the original
level or near it. Persons with poor adaptability to environmental
changes, including some with hypertension and neurocirculatory dystonia,
responded to the physical exertion with a much smaller decrease in the
effectiveness index. More economical blood circulation during physical
exercise is, in our opinion, an extremely important adaptive mechanism
which ensures a large increase in the energy requirements of the body
with minimum exertion of the cardiovascular system. In our observa-
tions, after measured physical exercise, the cardiac output rose by 65
percent on the average while the utilization of oxygen increased 3.23
times.
The adaptive reactions of the blood circulation to the energy re-
quirements of the body are based on the neuroendocrine connections of
the cardiovascular system with tissue metabolism that guarantee a prompt
and adequate response of the arterioles and capillaries to the require-
ments of tissue metabolism. Evidence for this also comes from the
16
direction and phase quality of the changes in the effectiveness index
during oxygen deficiency and breathing at a high pressure. There were
likewise individual differences in the responses due to qualitative
characteristics of the adaptive mechanism.
The following conclusions seem reasonable :
(a) The differences observed in blood circulation in relation to
oxygen utilization are connected with the state of the mechanisms of
blood circulation regulation.
(b) The value of the index of circulation effectiveness when the
body is at rest and undergoing various functional loads is of value in
qualitatively characterizing the functional state of blood circulation
in satisfying the energy requirements of the body.
(c) An evaluation of blood circulation effectiveness in relation
to oxygen utilization makes it possible to control more precisely the
systematic actions of various flight factors on the organism and to
determine the conditioning needed to be able to withstand them.
FUNCTIONAL CHANGES IN THE CARDIOVASCULAR SYSTEM AFTER
EXPOSURE TO HYPODYNAMIA
Yu. V. Vanyushina
In the course of human phylogenesis and ontogenesis, the cardio-
vascular system acquired, and is constantly training adaptive reflex
mechanisms to maintain blood circulation at an appropriate level under
the conditions of gravity. Movement, physical exertion, and change in
bodily position regularly stimulate the cardiovascular system. Thus,
the central nervous system receives a steady stream of impulses from
the cardiovascular receptors and activates the reflex mechanisms that
regulate blood circulation. Under the conditions of weightlessness
this stream of impulses might be expected to diminish considerably in
view of the limited muscular activity and complete exclusion of the force
of gravity in changing from a horizontal to a vertical position and vice
versa. We therefore thought it would be interesting to determine how the
cardiovascular reflexes that resist gravity might change in human beings
required to' remain a long time in circumstances that limit reflex impulses
from the muscles and cardiovascular system.
Two series of experiments were performed. The first series involved
subjects immobilized for 5 • 5-10 • 5 days in a special armchair in a position
77
of maximum muscular relaxation. The second series was performed with
subjects who remained suspended in a tank of water for 5. 5-11. 5 days.
In both series of investigations the subjects were assigned a regime of
maximum limitation of movements. The ground series consisted of 6 ex-
periments, the water series, of 3. All the subjects were essentially-
healthy males, 20-22 years of age.
An orthostatic test was used to evaluate the mechanisms of the
cardiovascular system responsible for adaptation to the force of
gravity. A change in bodily position from horizontal to vertical causes
gravitational forces to act on the blood. Due to hydrostatic pressure
the blood rushes down to the blood vessels of the abdominal cavity and
extremities. In the development of compensatory mechanisms, the effect
of hydrostatic pressure is compensated by an increase in vascular tone.
With inadequate compensation the aforementioned hydrostatic phenomena
cause the abdominal blood vessesl to dilate and overflow with blood
while the other parts of the body, including the brain, become anemic .
In the former, the maximum blood pressure either does not change or
actually increases owing to hypercompensation; in the second, it drops
unless it is secondarily compensated by an increase in the force and
frequency of cardia contractions.
Two types of orthostatic tests were used. One involved a table
turning along the horizontal axis with passive change of the subject's
position from horizontal to vertical. The pulse rate and arterial blood
pressure were measured every minute for 10 minutes before rotation and for
5 minutes afterward. The second test involved the subject's actively
changing from a sitting to a standing position. The same cardiovascular
indices were studied after 10 minutes in a sitting position and 1 minute
after changing to a standing position.
In taking the orthostatic test before exposure to hypodynamia, all
the subjects felt well with a pulse acceleration of 10-12 beats per min-
ute. The maximum blood pressure reaction ranged from -2 to +8 mm Hg,
the minimum, from +15 to +20 mm. According to the literature (A. L.
Vilkovyskiy, Martinet, Waldvogel, A. Gitter, and others), this is equiva-
lent to the normal reaction to a change in bodily position from horizon-
tal to vertical.
After prolonged exposure to hypodynamia, the cardiovascular reaction
to the orthostatic test changed considerably. Acceleration of the pulse
was greater than before the experiment by 20-^9 beats per minute. In the
experiments with hypodynamia for 5.5 days, we noted a slight impairment
of blood pressure regulation. The impairment was greater in the experi-
ments involving a longer exposure, i.e., a marked lowering (by 20 or
more mm Hg) of systolic pressure after the orthostatic test.
After long exposure to the water simulation of weightlessness,
dysfunction of the reflex mechanisms regulating cardiovascular activity
7 8
was even more pronounced, e.g., extreme tachycardia (acceleration of the
pulse by 50-7^ beats per minute) and a sharp drop in systolic blood pres-
sure (by 26 mm Hg). The minimum blood pressure showed a tendency to rise,
A sharp drop in maximum blood pressure with a simultaneous rise in mini-
mum pressure caused a marked decrease in pulse pressure (about 8-12
Hg). In some cases the subjects felt dizzy after rotation.
mm
We thought it would be interesting to study the chronotropic activity
of the heart (by N. P. Razumov's method) with an unconditioned orthostatic
stimulus while administering the above-described tests. Such a stimulus
activates the nerves that accelerate the cardiac rhythm. The method is
useful in judging the speed with which the regulatory mechanisms of the
heart are engaged after a change in position. After hypodynamia we
observed an increase in the intensity and, in some cases, a slowing of
the rate of development or pathological ability, instability of the
orthostatic and clinostatic reflex.
Observations of the change in intensity and rate of development of
Aschner's oculocardiac reflex revealed some sluggishness in the cardio-
vascular reflexes after hypodynamia. After the subjects remained in the
armchair or water for a considerable period of time, the oculocardiac
reflex decreased while the rate at which it developed slowed.
Thus, in human beings remaining for a long time under the conditions
of limited mobility, while lying in an armchair or in water, the adaptive
reactions of the cardiovascular system to the force of gravity decrease.
The weakening of these mechanisms is manifested, during an orthostatic
test, in a sharp acceleration of the pulse, drop in systolic and pulse
pressure, and slight cerebral anemia, as shown by vertigo.
One of the reasons for the decrease in the compensatory reaction of
the cardiovascular system to postural changes may be dysfunction of the
neuroreflex mechanisms that regulate cardiovascular activity, as shown
by decreased intensity, sluggishness, and unstable development of the
cardiovascular reflexes (in orthostatic and clinostatic tests, Aschner's
reflex) .
After prolonged exposure to weightlessness and return to gravitational
conditions, the preservation and maintenance of cardiovascular reactions
to the force of gravity are essential for the successful completion of a
flight. Hence, to enable man to remain in a weightless state for a long
period of time, it is highly important to devise ways and means of pre-
venting impairment of regulation of the cardiovascular system.
79
EFFECT OF SOME DRUGS ON TOLERANCE OF ACCELERATIONS
P. V. Vasil'y ev and V. Ye. Belay
The problem of increasing bodily resistance to the effect of ac-
celerations that occur at certain portions of flights of airplanes and
spacecraft is exceptionally important. Practical use is now made of
such methods as having the pilot assume a certain position with respect
to the acceleration vector, suitably designed seats, G-suits, physical
conditioning, etc. There are references in the Soviet and foreign
literature to the possibility of increasing resistance to accelerations
by using immersion systems (E. H. Wood et al., 19^3; 0- P- Mirolyubov,
1961 j Blake-Shador, B. Hensley, and R. Simmons, I96I; B. Blake -Sheffer,
1962; Silvan James, 1962; others), hibernation ("anabiosis") on space
flights (S. Pernes and A. Smith, i960; B. Blake-Sheffer et al., 1961),
and drugs (V. Ye. Kolla, 1953; K. G. Vasil'yev et al . , 1957 J R. Amirov,
1961 ; V. I. Danileyko, 1962; A. Skano and G. Meyneri, 196I; Greyner,
1956). This last approach deserves especial attention and study be-
cause a knowledge of the pharmacodynamics of the compounds, the nature of
their effect on different organs and systems, and the genesis of disturb-
ances can be used to change the reactivity of the body and increase its
resistance to various factors.
This report-^- presents some data obtained in experiments with sym-
pathomimetic amines (epinephrine, norepinephrine, amphetamine, phenatine
[condensation product of amphetamine and nicotinic acid], and ephedrine)
and anesthetics ( chloral hydrate and pentothal sodium) . Most of the
experiments were performed on white mice, a few on white rats, rabbits,
and dogs. The mice were the principal experimental animals because a
great many of them could be used. The survival rate was the criterion
of effectiveness in the experiments on the white mice and rats, while
changes in cardiovascular activity as traced on the EKG (standard leads)
and in respiration served this purpose in the experiments on the rabbits
and dogs .
Accelerations were produced in centrifuges with a radius of 3I cm
for the mice and rats and 3.7 m for the rabbits and dogs. In all the
experiments, the accelerations were transverse to the longitudinal axis
of the body.
Solutions of the drugs prepared just before use were injected in-
traperitoneally into the mice and rats and intravenously, subcutaneously,
or intramuscularly into the rabbits and dogs. The doses, methods, and
S. P. Kolchin and Ye. S. Sviridova participated in the research.
8o
times the drugs were injected and the intensities of the accelerations
applied in the individual experiments are noted below in the descrip-
tions of the results .
The very first experiments on rabbits subjected to accelerations
of 9 units for 6 minutes revealed that intramuscular injection of 0.17
mg/kg of norepinephrine 15- 30 minutes before rotation led to a delay-
in the onset of bradycardia, which, in the opinion of most investi-
gators, indicates a breakdown in the compensatory-adaptive mechanisms
of the cardiovascular system.
These findings are in complete agreement with the results of the
experiments of A. Skano and G. Meyneri (1961) with positive accelerations.
We emphasize that in our experiments not only did cardiac activity in
the compensation stage persist longer in response to the accelerations,
but, what is just as important, the degree of decomposition, judging
from the bradycardia, was much less pronounced.
Some experiments with intravenous injection of 0.025 mg/kg to 0.1
mg/kg of norepinephrine 2-3 minutes before rotation produced contradic-
tory data, which required special experimental analysis. The results of
the investigations on the white mice were equally contradictory. In
some experiments there was a marked increase in the survival rate, but
a decrease in others. It was impossible here to detect any relation-
ship between the dose of the drug (from 0.2 mg/kg to 5 rog/kg) or time
it was injected (from 10 to 60 minutes before rotation).
The administration of 0.1-1 mg/kg of epinephrine to white mice had
similar results. For example, when determining the effectiveness of
epinephrine from the LD^q in one experiment, the resistance of the ani-
mals to the accelerations increased by 6.5 units, but decreased by 5.2
units in another.
Thus, the results of our investigations do not permit any final
judgment on the effect of epinephrine and norepinephrine on the resist-
ance of animals to accelerations. As noted above, besides these two
drugs, we also tested amphetamine, phenatine, and ephedrine. The best
results were achieved with amphetamine and ephedrine .
Experiments with amphetamine were performed on 792 white mice with
a determination made of both the survival rate of the control and experi-
mental animals exposed to a constant intensity (5O-55 units) of accelera-
tion and time of action (10 minutes) and the median lethal dose (LD_ )
of acceleration measured by Berens ' method (1929). A substantial number
of experiments were run in order to determine the dose and time to inject
the drug before rotation. .
81
Table 1. Results of Determining Control and Experimental
(Amphetamine) Mouse Tolerance of Lateral Accelerations by
Berens ' Method (LD,- ) (Rotation Time - 10 Minutes)
-^-
No. of
revolutions
of centrifuge
O
Experimental
data
Integration
■p
U
O
O
Died
Survived
Died
Survived
Total
>3
-P
•H
H
-P
Sh
O
US
Pi
31+0
4
4
18
18
36O
4
1
3
1
14
15
6.6
380
4
2
2
3
11
14
21.2
1+00
4
3
1
6
9
15
40.0
61.0
420
4
1
3
7
8
15
46.7
Units
44o
4
2
2
9
5
14
64.3
460
4
3
1
12
3
15
80.O
480
4
2
2
14
2
16
87.3
500
4
4
18
18
100.0
340
4
4
23
23
36O
4
1
3
1
19
20
5.0
380
4
1
3
2
16
18
11.0
400
4
1
3
3
13
16
18.7
69.7
420
4
1
3
4
10
14
28.3
Units
440
4
1
3
5
7
12
41.7
82
Table 1 (Continued)
No. of
O
•H
e
Experimental
data
Integration
-p
05
-P
revolutions
of centrifuge
o
o
Died
Survived
Died
6
Survived
Total
•H
H
cd
P
o
s
O
m
o
k60
1+
1
3
k
10
6o.o
^80
u
3
1
9
1
10
90.0
500
4
k
13
13
100.0
1
^-P a
N 2 -R
900
where n is the intensity of acceleration, N is the number of revolu-
tions, and R is the size of a centrifuge arm in meters.
The results showed that after intraperitoneal injection of 0.8-1
mg/kg of the drug I5-3O minutes before acceleration, the resistance of
the mice, as determined from the LD^-q, rose. For example, resistance
in the animals given 0.9 mg/kg of amphetamine was 8.7 units higher than
in the control (Table l).
After a dose of O.I-3.O mg/kg, the positive effect of amphetamine
decreased, but after a dose of 5.0 mg/kg the effect was negative.
Highly satisfactory results were also obtained with the other
sympathomimetic drug - ephedrine (Table 2).
It is evident from the figures in Table 2 that the most potent
effect followed intraperitoneal injection of 0.5 mg/kg of ephedrine.
Halving the dose reduced to zero its effect on the animals ' resistance
to accelerations, while increasing the dose decreased the positive
effect.
The experiments in which the LDcq was determined revealed that
injection of 1.0 mg/kg of ephedrine increased the experimental mice's
resistance by about 7 units as compared with the control (from V7.5 to
83
Table 2. Effect of Ephedrine on the Survival Eate of
Experimental and Control White Mice Subjected to
Lateral Accelerations with an Intensity of 55 Units
Group of animals
No. of mice
in the group
Outcome
Survival rate,
Died
Survived
percent
Control
0.25 mg/kg of
ephedrine
20
20
11+
Ik
6
6
30
30
Control
0.5 mg/kg of
ephedrine
38
38
30
2k
8
Ik
21
36.9
Control
1.0 mg/kg of
ephedrine
60
60
kk
ko
16
20
26.6
33-^
5I4. units). Increasing the dose to 10.0 mg/kg reduced the LD from 1+7-5
units in the control to 1+1+.6 units in the experimental group.
Experiments are now under way on rabbits. Intramuscular injection
of 20.0 mg/kg of ephedrine had a negative effect, but 5.0 mg/kg had a
slight positive effect. Experiments with this drug are continuing,
mainly to find the optimum effective dose and optimum times of injecting
the drug.
Thus, the results of our experiments and the published data (T.
Greyner, 1956; A. Skano and Meyneri, 19^1; others) indicate that several
sympathomimetic amines have a distinctly favorable effect on resistance
to accelerations. The mechanism of this action is still unclear. To
attribute it solely to the effect on vascular tone, as some authors do,
is scarcely possible. The increase in resistance is evidently due to
the more complex nature of the action of the drugs on several functional
systems (cardiovascular, nervous, endocrine, etc.). Special investiga-
tions will be needed to elucidate these mechanisms.
To date little systematic work has been done in studying the effect
of anesthetics on tolerance of accelerations. In his dissertation, V. I.
Danileyko (1962) merely mentions that in experiments on white rats he
observed a 16-1+0 percent increase in the survival rate as compared with
the control after subcutaneous injection of 50 mg/kg of sodium amytal.
On the other hand, according to the incidental observations of B. S.
Savin, anesthetized dogs showed a deterioration in the condition of the
8U
compensatory mechanisms responsible for keeping blood pressure in the
vascular bed constant. Intact animals withstood circulatory impairment
after exposure to accelerations up to an intensity of 5-6 units; anes-
thetized animals did so only up to an intensity of 2-3 units.
We studied the effect of two anesthetics on tolerance of accelera-
tions: chloral hydrate, which acts chiefly on the cerebral cortex, and
pentothal sodium, which acts chiefly on the subcortex. We tested both
large doses, which caused deep anesthesia with a loss of reflexes to
pain, and small doses, which produced only mild general inhibition, as
manifested in decreased motor activity and sleepiness.
Experiments on white mice and rats revealed that the injection of
200 mg/kg of chloral hydrate 15 minutes before the start of rotation
increased resistance by 2-10 units, as determined from the LD.= q, where-
as a lj-00 mg/kg dose reduced it from 65 to h8 units.
A dose of 30 mg/kg of pentothal sodium increased tolerance of ac-
clerations by i+-19 units, but a 100 mg/kg dose reduced it by lit. units.
The variable response to the same doses of anesthetics (all the
other conditions were equal) was evidently caused by individual pecu-
liarities both in the reaction to the anesthetic and in the reaction to
subsequent exposure to the accelerations. The negative results of the
experiments with large doses of chloral hydrate and pentothal sodium
were probably due to a lowering of the function of the compensatory-
adaptive mechanisms of the organism in response to the unusually strong
environmental stimuli. Similar results were obtained in many other
investigations (Ye. V. Guber, 1950; T. Ye. Kudritskaya, 1950; I. R.
Petrov, 1952; others) dealing with the effect of different forms of
oxygen deficiency.
Thus, analysis of our own and published data show that by using
drugs to change the functional state of the organism, one can increase
its resistance to accelerations.
The aim of future investigations should be to find highly effective
and conveniently administered drugs that most satisfy the requirements
of specific flights.
8 5
STRUCTURAL AUD CYTOCHEMICAL INVESTIGATIONS OF THE UTRICLE
UNDER THE CONDITIONS OF RELATIVE REST AND
AFTER EXPOSURE TO ACCELERATIONS
Ya. A. Vinnikov, 0. G. Gazenko, L. K. Titova, A. A. Bronshteyn,
and V. I. Govardovskiy
1. Although the significance of the utricle (a membranous sac
located in the vestibular part of the labyrinth) in maintaining muscular
tone has been adequately studied, the mechanism of function of this
organ, which senses the position of the human and animal body in a grav-
itational field, is still obscure. Studies of its substructural and
cytochemical organization both under the conditions of relative rest
and after exposure to accelerations or weightlessness are of consider-
able interest in this respect. They may well provide the key to an
understanding of the mechanism and regulation of function of the organ
under the aforementioned conditions.
2. An electron microscopic study of the utricle of mammals (guin-
ea pigs and rhesus monkeys) and birds (pigeons) at relative rest re-
vealed the presence of evolutionary gradations reflecting the ecological
conditions of locomotion of these animals in a gravitational field.
The utricle of these animals contains columnar hair cells supplied with
button-like synapses, as well as jug-shaped sensory cells enclosed in
cup-shaped synapses. In this cup the guinea pigs have only 1, the mon-
keys 2, and the birds about 5 hair cells. The substructural organiza-
tion of the columnar hair cells differs from that of the jug -shaped
hair cells with respect to the nucleus, shape, and size of the mito-
chondria, shape and location of the synaptic vesicles, structure of the
synaptic membranes, etc. There are also differences in the distribution
and location of the ribosomes, which in the hair cells are generally not
underlain by membranes of the endoplasmatic network. In guinea pigs,
the ribosomes are found only in the basal part of the sensory cell under
the nucleus, whereas in monkeys and pigeons they can also be found in the
apical part of the sensory cell. However, the distribution and struc-
ture of the hairs (of one kinocilium and cluster of stereocilia), which
crown the hair cells and support the otolithic membrane with otoliths,
remain unchanged in all the animals investigated.
3. Cytochemical investigations of the distribution and activity
of several biologically active substances (DNA, RNA, total protein,
86
functional protein thiol and carboxyl groups, some mucopolysaccharides,
oxidation enzymes, and acetylcholinesterase) in the hair cells of the
guinea pig, monkey, and pigeon utricle under conditions of relative rest
likewise revealed ecologically related resemblances and differences in
cytochemical organization, which can be superimposed on the substruc-
tural equivalent and which characterize the basic energy processes of
their vital activity. For example, KNA (bound with the ribosomes) in
guinea pigs is generally located only in the basal part of the hair cell.
In monkeys and pigeons, RWA (bound with the ribosomes) is located both in
the basal part of the cell and at its apical pole. The activity of the
oxidation enzymes in the mitochondria of the synapses of the utricle hair
cells is more intense than in the intracellular mitochondria. Acetyl-
cholinesterase is found in all cases only near the synapses. The con-
tent of total protein, functional groups, and mucopolysaccharides may
vary in different utricle structures, but it remains unaltered in the
hairs of the hair cells and otolithic membrane in all the animals inves-
tigated .
k. After accelerations of 10 g lasting 3 minutes and repeated 5
minutes, 1 hour, 2 hours, 3 hours, 8 hours, and 2k hours later, the
hair cells of the animals revealed similar specific changes along with
some differences related to the substructural and cytochemical organiza-
tion of the different animals. The passage of nucleolar RMA from the
nucleus into the cytoplasm observed in the basal part of the guinea pig
hair cell after acceleration was confirmed and interpreted with the
electron microscope. After the first rotation and, especially, after
multiple ones, there was a polar "filtration" of the ribosomes through
the pores of the nuclear membranes into the cytoplasm of virtually all
the hair cells, where they induced the formation of a spherical area in
the endoplasmatic network, in which intense protein synthesis seemed to
take place. In the monkeys and pigeons, however, similar processes oc-
curred mainly in the columnar hair cells with the button-like synapses.
The outer nuclear membrane in all the sensory cells becomes
"detached" and forms characteristic folds, apparently due to changes
in nuclear processes during intensified functioning caused by accelera-
tion.
The decrease in activity of the oxidation enzymes after accelera-
tion is generally accompanied by some swelling of the mitochondria and
change in the electron density of their membranes and cristae.
The decrease in activity of acetylcholinesterase in the synaptic
region is accompanied by some changes in the synaptic membranes and
synaptic vesicles (containing acetylcholine) and in their relations
with the mitochondria.
Finally, hairs of the hair cells (stereocilia) and the otolithic
8 7
membrane undergo changes in the location and content of some mucopoly-
saccharides after acceleration.
5. The changes in structural and cytochemical organization of
hair cells in the synapses of the utricle after acceleration are appar-
ently characteristic of them in a state of excitation and transmission
of impulses. This state is accompanied by a chain of biochemical pro-
cesses that take place in a strictly determined substructural location.
These processes are related, first, to nucleic acid function (i.e., pro-
tein synthesis); second., to oxidation enzyme activity (i.e., tissue
respiration); and, third, to acetylcholinesterase activity (i.e., the
cholinergic mediator system) .
Our findings throw some light on the mechanism of function of the
organ of gravitation on the subcellular level of organization. There is
reason to believe that it can be regulated under the conditions of space
flight. However, the processes of specific stimulation of the utricle
and the interlinking of its activity with the other receptor sections
of the vestibular apparatus are still obscure. Their elucidation is on
the research agenda.
OXYGEN SUPPLY OF THE HEART DURING RESPIRATION AT EXCESS PRESSURE
V. G. Voloshin
Numerous investigations have shown that respiration at excess
pressure causes marked functional body changes, notably in the respira-
tory and cardiovascular systems: the heart assumes a heavy load and is
compelled to function under unfavorable conditions. Data suggest that
studies on the blood and oxygen supply of the heart under these condi-
tions would undoubtedly be of theoretical and practical interest.
There are no experimental data in the Soviet and foreign litera-
ture on the state of the coronary blood flow, myocardial temperature
and oxygen tension therein during respiration at excess pressure. The
first investigations of this kind were carried out on dogs by a group
of scientists under the direction of D. I. Ivanov, who found that ex-
cess pressure reduces the rate of blood flow in a phasic manner, ex-
tent of reduction varying with amount of excess pressure. After respi-
ration is excluded, the rate of blood flow increases sharply, sometimes
above the original level, after which it returns to normal. The use of
a compensating suit slows the reduction in the rate of blood flow.
88
We performed a series of chronic and pressure -chamber experiments
on the coronary blood flow of dogs breathing at excess pressure. The
volumetric blood flow rate was determined by the thermometric method
as modified by M. Ye. Marshak and recorded on an ink -writing instrument
of the "Mikrograf" type. We constructed a special attachment that made
it possible to record on highly sensitive scales using the entire width
of the tape (210 mm) . This attachment was later used to record the tem-
perature. We recorded, also, the EKG, EMG, pneumogram, and pressure
under a mask.
The operations, performed under sterile conditions, used morphine-
urethan anesthesia, with artificial respiration carried out by M. Ye.
Marshak and G. N. Aronova's method. The experiments were run after the
animal recovered (starting the Jth. day).
Blood -flow reactions did not differ significantly in the acute and
chronic experiments, nor were any differences noted between the reactions
of the intact and anesthetized animals in the chronic experiments.
After exposure to noncompensated excess pressure, there was gen-
erally a decrease in the coronary blood flow followed by a slight in-
crease. Later, a slight temporary increase alternated with a decrease.
In the acute experiments the blood flow reaction to excess pressure was
more uniform and usually took place in three phases: decrease, partial
increase, decrease. These differences in the blood -flow reaction of the
intact and anesthetized animals may have been due to the fact that the
adaptive reactions of the anesthetized animals were less complete.
Moreover, there was no situational reaction or emotional factors, and
individual characteristics were less pronounced.
The exclusion of excess pressure was accompanied by an increase
in the blood flow above the original level followed by a return to
normal. Sometimes there was an initial brief increase when the excess
pressure was slight. When external compensation was used, there was a
decrease in the blood flow after high (over 300 ™ HgO) excess pressure.
Altitude experiments, with oxygen supplied by a serial KX0-3 were
carried out in a pressure chamber with a smooth increase in ambient
pressure corresponding to altitudes up to 30,000 m followed by the ani-
mals remaining at the particular "altitude".
Elevation in the pressure chamber frequently caused an increase
in the coronary blood flow—highly pronounced in some animals--and was
most likely due to a manifestation of the orienting reflex to unusual
stimuli (the situation and noise of the machinery operating the chamber).
Apparently these changes became conditioned reflexes.
I
89
The turning on of excess pressure caused a more or less appre-
ciable increase in the blood flow. In some animals, as the pressure
and "altitude" increased, the blood flow decreased, giving way to an
increase at high "altitudes". In other animals, this decrease did not
occur and elevation was accompanied by an increase in blood flow.
Starting with an "altitude" of 20,000 m (sometimes sooner, sometimes
later), marked fluctuations frequently appeared on the blood -flow curve.
When they remained at the particular "altitude" (30,000 m or 20,000 m
in some animals), first a slow, then a steep, drop in the blood -flow
curve down to zero on the instrument took place against a background of
fluctuations in the blood flow. After the "descent", the blood flow in-
creased sharply and remained for a long time above the original level.
The decrease in coronary blood flow when breathing at excess
pressure suggests that the myocardium was inadequately supplied with
oxygen under these conditions (there actually were EKG changes charac-
teristic of myocardial hypoxia) .
These findings led us to carry out additional investigations
along the same lines. An acute experiment studied oxygen tension in
the myocardium of the left ventricle by the polarographic method. When
breathing at excess pressure, oxygen tension in the myocardium dropped
in proportion to the amount of pressure. After the pressure was turned
off, the polarogram slowly returned to the original level.
These results confirm our earlier finding that excess pressure
causes myocardial hypoxia, the degree varying with the amount of pres-
sure.
The temperature of the myocardium of the left ventricle was
measured under the same conditions. Breathing at excess pressure reg-
ularly caused a distinct elevation of myocardial temperature after a
decrease in the coronary blood flow. This increase may be sharply
intensified in the case of poor tolerance of excess pressure and in
some instances amount to O.65 C even with slight excess pressure.
With good tolerance of the pressure, the temperature rises more slowly
and is periodically stabilized. However, even in these instances the
temperature increase is of the order of O.3-O.5 .
The use of external compensation significantly decreases these
temperature changes. When the pressure is turned off, the temperature
at first drops quickly, then slowly, but usually remains above the orig-
inal level, stabilizing after 2-5 minutes.
An elevation of temperature in a functioning organ may be re-
garded as an index of the intensity of the metabolic processes and the
concomitant heat production. There are indications that disruption of
metabolism, e.g., interference with the cycle of oxidizing
90
phosphorylation , causes an increase in heat production.
Temperature changes appearing in the myocardium after exposure
to excess pressure take place much more slowly than do blood flow-
changes. This is evidence in favor of the metabolic character of these
changes. However, one must also take into account the state of the re-
gional blood flow, which can apparently introduce its own corrections
into the temperature of an organ. In this connection, it is pertinent
to note that myocardial temperature always rises after a decrease in the
coronary blood flow.
With reference to the condition of our experiment, it is more
plausible to believe that the temperature of the myocardium reflects
the relationship between heat production and heat removal from the blood
flowing out of the functioning heart. At excess pressure this balance
between heat production and heat removal is upset with a decrease in heat
removal and, possibly, with an increase in heat productions as well.
ENSURING BADIATION SAFETY ON THE FLIGHTS OF ASTRONAUTS
YU. A. GAGARIN, G. S. TITOV, A.G. NTKOLAYEV, AND P.R. P0P0VICH
Yu. M. Volynkin, V. V. Antipov, N. N. Dobrov,
M. D. Nikitin, and P. P. Saksonov
Recent advances in science and technology have made it possible
to study the physical parameters and biological effects of cosmic radia-
tion, and to ensure the radiation safety of space flights.
In an orbital flight of the Vostok, the astronaut is exposed to
primary cosmic radiation (galactic rays) and bremsstrahlung arising
from the interaction of electrons in the outer radiation belt with the
shell of the vehicle. Nor can one rule out the possibility of slight
irradiation by protons of the inner radiation belt, which comes down,
e.g., in the region of the Brazilian magnetic anomaly, to altitudes of
230-320 km.
According to the data of S. N. Vernov et al. and V. Ye. Nesterov
et al., at altitudes of 180-3^0 km with a 65 tilt in the orbit, approx-
imately 90 percent of the absorbed dose is due to primary cosmic radia-
tion, 10 percent to radiation of the earth's radiation belts. It will
be noted that primary cosmic radiation is composed of strongly ioniz-
ing heavy nuclei which may produce nuclear splitting ("stars") in a
-»,
91
biological object. In view of the biophysical characteristics of the
action of the heavy component, it is to be expected that the biological
effectiveness of this kind of radiation will be substantially higher
than the effectiveness of X-rays or 7-rays.
Measurements made on satellites 2-5 and the Vostoks showed that
at these heights the integral daily dose of radiation fluctuates between
8 and 15 millirads (mrad) . It is obvious that even with allowance made
for the high biological effectiveness of the heavy component of primary
cosmic radiation, the radiation dose received during short flights at
altitudes of 180-250 km is not dangerous.
A real threat to the astronaut's health at these altitudes comes
from the protons produced during chromospheric flares on the sun.
Solar protons possess an energy of several Mev to 700 Mev, although in
some cases they may attain an energy of several Bev.
After major solar flares, the intensity of cosmic radiation at
great distances from the earth grows a 1,000-fold and even 10,000-fold
outside the magnetic field, causing a vast increase in the doses up to
lethally dangerous levels of the order of 500 rad or more. On orbits
of the Vostoks, the screening effect of the earth's magnetic field has
an effect, the radiation dose decreasing to several dozen rad per burst.
Since solar flares do not occur at regular time intervals the probabil-
ity of striking a flare of varying intensity depends on the average
probability of its appearance and the duration of the flight.
Besides the protons of solar flares, astronauts Nikolayev and
Popovich were endangered by the ionizing radiation caused by the high-
altitude nuclear blast set off by the U.S. over Johnston Island in the
Pacific on July 8, 1962.
In light of the foregoing, the radiation protective measures
for the Vostok flights called for:
(a) Forecasting the radiation situation in space.
(b) Measurement of the integral dose and dose rate on the space-
ship itself.
(c) Biological dosimetry of cosmic radiation.
(d) Use of antiradiation drugs in emergency situations.
A service was organized to forecast radiation activity in space,
which observed solar activity both before and during the flight. Astro-
physical observatories and heliophysical stations in different parts of
the Soviet Union made continuous optic, magnetic, and radio observations
92
of the sun. In addition, the intensity of radiation in the upper layers
of the atmosphere was directly measured by instruments carried on sound-
ing balloons sent up 6-8 times a day from different parts of the USSR,
including the polar regions. The information thus obtained was of great
value to the flight managers.
Radiation safety was enhanced by (l) structural features that pre-
vented cosmic radiation from penetrating the cabin of the spacecraft
and protected it from the effects of the radiation caused by the high-
altitude nuclear blast, and (2) antiradiation drugs to be taken in case
the radiation situation deteriorated greatly.
Vostok and Vostok 2 were monitored by individual ILK and IFK do-
simeters and thermoluminescent glasses. The total dose absorbed by
Gagarin and Titov was 0.6 + 1.5 mrad and 12 mrad, respectively. Due to
the greater length of the flights of Vostok 3 and Vostok k, special do-
simeters were installed and the readings were transmitted via telemetry
to ground observation stations. Moreover, the set of individual dosime-
ters was increased. A. F. Nikolayev and P. R. Popovich had a DKP-50,
thick photoemulsions, etc. besides the dosimeters available to Gagarin
and Titov.
According to the dosimeters on board, the total dose during the
flights of Vostok 3 and Vostok k was U3 + 1 mrad and 32 + 1 mrad, re-
spectively (C. N. Vernov, I. A. Savenko et al.). The readings of the
individual DKP-50 dosimeters did not exceed the errors caused by self-
discharge. According to the data provided by the individual dosimeters
placed on the astronauts, Nikolayev 's absorbed dose ranged from kQ to
6k mrad, Popovich' s - from 37 to h6 mrad (I. B. Keyrim-Marjus et al.).
The set of detectors of ionizing radiation placed in the living
quarters made it possible to evaluate the radiation conditions in which
the biological experiments were performed. Judging by the thick photo-
emulsions and scintillation counters, the integral dose in these areas
on Vostok 3 and Vostok h was 56 + 8 mrad and U5 + 7 mrad, respectively,
during the flight. The contribution of the charged particles to the
integral dose constituted about k0 percent of the amount, some two-
thirds of the contribution consisting of heavy nuclei (Z l).
According to the data provided by the IFK and ILK dosimeters, the
total dose during the flight was about 5O-6O mrad (V. N. Lebedev, V. S.
Morozov et al . ) . Thus, the mean dose rate of radiation during the
flights of Vostok 3 and Vostok k was 13 + 2 mrad/2U hours, i.e., it was
above the dose rate on the Vostok (7.2 mrad/2U hours) or Vostok 2 (d.k
mrad/2J+ hours). The increase in dose rate may have been due to possible
residual radiation arising from the high-altitude nuclear blast of
July 8, 1962.
93
It is evident from the above-mentioned measurements that the inte-
gral doses detected by various methods agree with each other within the
limits of measurement errors. These doses do not exceed the standards
established for persons working with sources of penetrating radiation
and they do not endanger human health.
Besides various instruments, the spacecraft carried an assortment
of biological specimens (air-dried plant seeds (wheat, pea, onion, pine,
cabbage, beet, etc.), microspores of Tradescantia paludosa, a lyosogenic
culture of E. coli K-12 (\), Drosophila melanogaster, human cancer cells,
and Ascaris suum eggs) for biological monitoring of cosmic radiation and
for investigation of the injurious effects of space flight factors, in-
cluding ionizing radiation, on hereditary structures and physiological
functions of the individual cell and of the organism as a whole.
It will be noted that the results of the radiobiological investi-
gations agree very nicely with the physical measurements. These experi-
ments showed that genetic tests can be used to determine the injurious
effect of space factors on the hereditary structures of certain objects.
For example, various disruptions of mitosis were discovered in wheat
shoots (V. V. Khvostova et al.), tradescantia microspores (N. L. Delone
et al.), an inducing effect in lysogenic bacteria, etc. (N. N. Zhukov-
Verezhnikov et al.). These changes were probably caused by a number of
flight factors, including ionizing radiation. It is also possible that
such factors as vibration and accelerations may sensitize certain objects
to cosmic radiation and thereby permit ionizing radiation to become ef-
fective in much smaller doses. On the other hand, the physiological
methods used failed to detect any significant changes in the activity of
other objects under the influence of flight factors.
Clinical observations and special laboratory tests made on Ga-
garin, Titov, Nikolayev, and Popovich at regular intervals since their
flight also clearly confirm the fact that cosmic radiation did not im-
pair their health.
It may therefore be stated that results to date testify to the
effectiveness of the measures used to ensure radiation safety during
manned flights on spacecraft of the Vostok type.
94
CHANGES IN CARDIAC ACTIVITY DURING PROLONGED LATERAL
ACCELERATIONS
A. D. Voskresenskiy
Experiments herein described stem from this fact: intense lat-
eral accelerations may cause myocardial hypoxia and cardiac disorders
(Muller, 196l ; Barer, 1962; C. Vacca and L. Vacca, I962) . In acute
experiments on anesthetized dogs, we investigated the oxygen content of
blood specimens obtained before and during accelerations (from an artery
and coronary sinus), measured the amount of blood flowing out of the
sinus in 1 minute, and recorded EKGs in standard leads. Respiration
was maintained with a DP-2 apparatus and constant ventilation. Accelera-
tions of 3} 6, and 9 g lasted 1, k, and 1 minute, respectively. In 91
experiments, a tray with a dog was secured at a 90° angle to the iner-
tial force (back-chest acceleration; in lk experiments - at a 45° angle
(equal back-chest and pelvis-head components of acceleration).
The oxygen content of arterial blood in the first minute of ac-
celerations of 3 and 6 g remained at about the original level. In the
if-th minute of acceleration of 3 gj it decreased moderately in most
cases; in the Vth minute of acceleration of 6 g, the decrease was gen-
erally very sharp. Acceleration of 9 g significantly reduced the 2
in the first minute.
The relationship between O2 content of arterial blood and inten-
sity and duration of acceleration is clearly reflected in the change
in mean values (Table l).
In the blood flowing out of the coronary sinus, the mean 2
content decreased in the entire series of experiments (Table 2) . A
comparison of the figures in Tables 1 and 2 shows statistically validated
correlation between the degree of decrease in 2 in arterial and venous
coronary blood .
It is also worth pointing out that the amount of oxygen in cor-
onary sinus blood decreased even in the many experiments where the
oxygen content of arterial blood rose (the 3 g, 1 minute series).
In the first series of experiments the arteriovenous difference
in oxygen increased somewhat on the average; in series 2 and 3> there
was virtually no change; in series k and 5, it decreased. An unusually
large decrease in the arteriovenous difference occurred in the i)-th min-
ute of an acceleration of 6 g owing to a sharp reduction of 2 in
arterial blood .
95
Table 1. 2 content of arterial blood specimens before and
during accelerations
Nature of
Action
No. of ex-
periments
Before ac-
celeration
During
3 g, l
minute
3g,^
minutes
6 g, 6'g, 9 g,
1 minute 4 minutes 1 minute
30 14 30 15 16
16.4+0. 57 l6.3tO.U6 16.3+1.3 16. 4+1.7 16.5H.2
l6.8-tO.7i i5.lto.85* 16.0+1.4 12. 0±i. 7* 13.3+I.I*
Note. The + sign is followed by the value of the standard devia-
tion of the mean value; * statistically significant difference in
mean values.
Table 2. 0^ content of blood flowing out of the coronary sinus
before and during acceleration
Nature of
Action
3 g, 1
minute
3 s, +
minutes
6 E, 6 g, 9g,
1 minute 4 minutes 1 minute
No. of ex-
periments
30
14
30 15
16
Before ac-
celeration
5-3±0.4l
4.8+0.49
4.0*1-99 5- 2*1.87
4. 9*0. 61
During
+•7+0.48
3.4+0.45*
3.5*0.90 3-Otl.O*
3.7+0.52*
96
Although the rate of blood outflow from the coronary sinus usu-
ally rose substantially j it dropped in a relatively small number of
experiments, rarely exceeding 25 percent of the initial value.
EKG changes generally corresponded to those described by other
authors after lateral accelerations, the degree of change varying con-
siderably from experiment to experiment and showing a distinct connec-
tion with the dynamics of outflow from the sinus. In the experiments
in which the rate of outflow increased, the EKG changes were compara-
tively slight and quickly disappeared after the centrifuge was halted.
The pulse rate remained constant throughout. Only in rare cases was
there sinus arrhythmia and solitary ventricular extrasystoles . In the
experiments with decreased outflow, all EKG changes were sharper and
persisted longer after termination of accelerations. There was often
a progressive decrease in the cardiac rate, marked arrhythmia, extra-
systole, and sharp changes in the QRST complex, symptoms indicative of
myocardial hypoxia and cardiac disturbances.
When the tray was placed at V?° angle to the accelerations, the
minute outflow from the sinus decreased sharply in almost all the ex-
periments. The period of stable pulse and relatively minor EKG changes
was only 15-20 seconds in some cases. The EKG changes were much more
pronounced than in the experiments with purely lateral acceleration.
Analysis of results clearly shows that lateral accelerations in-
creased the heart's oxygen requirement, as revealed by the regular de-
crease in 02 content of the coronary sinus blood with a simultaneous
increase in the outflow of sinus blood. Maintenance of a fairly high
level of coronary blood flow seems to be a basic factor that compen-
sates for the heart's increased oxygen requirement. With a decrease in
the outflow from the sinus, cardiac disturbances arose even when the
0g content of arterial blood did not decrease during acceleration. Yet,
despite marked impairment of blood oxygenation in the 4th minute of
acceleration of 6 g, we failed to observe a single instance of arrhyth-
mia or pulse deceleration if the outflow from the sinus remained high.
However, an increase in outflow cannot be regarded as an absolute
sign that the oxygen supply to the heart is adequate. In some cases,
especially with a sharp decrease in the 2 content of arterial blood, the
blood -flow rate may be maximal and unable to prevent the development of
myocardial hypoxia (6 g, k minutes).
Impairment of blood oxygenation intensifies the compensatory mech-
anisms, as is shown by a correlation between the 2 content of arterial
blood and the degree of myocardial uptake of oxygen from the blood.
The experiments in which the tray was tilted at a 45° angle show
that the hemodynamic changes arising after exposure to the head-pelvis
^f\
91
component of acceleration impair the blood supply of the myocardium and
promote cardiac disturbances.
INTERRELATION OF HEMODYNAMIC CHANGES AND RESPIRATION
DURING ACCELERATIONS
P . F . Vokhmyanin
Many investigators have noted that changes in respiration take
place during accelerations . Pulmonary ventilation usually decreases
in relation to intensity of acceleration because of contraction of the
diaphragm, abdominal pressure, and lowering of the ribs. Contraction
of the diaphragm results in inspiratory expansion of the lungs. The
lengthening of the period of exhalation is caused by laryngeal resist-
ance to exhalation, leading to an increase in intrapulmonary pressure
(strain). This complex protective re flex- -regularly observed in jumps,
collisions, lifting of weights, etc. --is well-known to fliers who use
the method of straining during accelerations. Breathing with straining
on exhalation, according to J. Fulton (19^8), increases fliers' toler-
ance of accelerations by 2.k g on the average. However, Valsalva's ex-
periment produced a favorable result with half the accelerations, show-
ing the significance of an optimal level of intrapulmonary pressure and
cyclicity in its rises.
Measurements of intratracheal pressure in deeply anesthetized dogs
showed a rise after a "head-pelvis" acceleration of 3 g to 9 mm Hg, 5 g
to 6 mm Hg with rapid breathing and to 12 mm Hg with slow breathing (200
mm Hg). With shallower anesthesia, intratracheal pressure during accel-
eration increases even more : acceleration of 3 g to 20-2^ mm Hg, 5 g to
15 mm Hg. After repeated accelerations, with cumulation of the effects,
the intensity of intratracheal pressure varies with the intensity of
acceleration- -with 3 g it rises less, but with 5 g it increases to 27
mm Hg.
Experiments with respiration at high pressure have shown that vas-
cular tone and venous pressure increase after such elevations of intra-
pulmonary pressure.
In our experiments, blood pressure was measured simultaneously in
the carotid and femoral arteries before and after tracheotomy. The
degree of change in pressure during accelerations varied with the depth
of anesthesia. In deeply anesthetized animals, pressure in the femoral
artery before the tracheotomy increased two-fold after an acceleration
98
of 3 g to 180 mm Hg, h- g - to 230 mm Hg. Blood pressure in the carotid
artery fell to k-2 and 17 mm Hg, respectively. After the tracheotomy,
pressure in the femoral artery rose only after 10 and 7 minutes of
accelerations to I32 and 160 mm Hg. Pressure in the carotid artery fell
to before the acceleration reached 3 £•
With weak anesthesia, arterial pressure during acceleration was
higher. Intrapulmonary pressure on exhalation and venous pressure
were also higher. Whereas the level of venous pressure in the deeply
anesthetized animals during acceleration was close to the theoretical
calculations of hydrostatic pressure of liquid in proportion to the in-
tensity of acceleration, in the weakly anesthetized animals it was much
higher than the theoretical value.
The arteriovenous difference in blood pressure decreased in the
paired arteries, although it occasionally leveled out, despite the high
arterial pressure. The increase in resistance to the flow of blood in
the major blood vessels and aorta under these conditions (along with
increased cardiac activity) seems to be a factor in the elevation of
arterial pressure in these vessels, and this should have compensatory
value for the shifting of blood therein in the direction of action of
the acceleration. This mechanism of compensation is impaired by tra-
cheotomy while the reflex mechanisms in the receptor zones of the vas-
cular bed obviously become slowed.
This complex protective reflex with the pressor effect that the
organism executes by raising intrapulmonary pressure on exhalation has
compensatory value in accelerations owing to its many-sided influence on
cardiovascular activity:
First, the elevation of intra-abdominal and intrathoracic pressure
may exert pressure on the surface of the major blood vessels in these
cavities and narrow their lumen and capacity.
Second, the elevation of intrapulmonary pressure is accompanied by
increased vascular tone, a phenomenon known from experiments with
breathing at excess pressure in a mask.
Third, the elevation of venous pressure observed under these condi-
tions of respiration increases resistance to the flow of blood in ar-
teries paired with these veins.
It follows from the foregoing that the rate of blood flow during
accelerations sometimes slows, despite the elevation of arterial pres-
sure in that part of the body toward which the hemodynamic changes are
directed. Although investigators often take elevated arterial pressure
as a sign of improved hemodynamics during accelerations, nevertheless,
unlike normal blood circulation conditions, stasis may result from
99
accelerations. Some investigations have revealed an impairment of
higher nervous activity in animals during "head -pelvis" accelerations
despite a fairly high level of pressure in the carotid artery (Sulimo-
Samuyllo et al.). Under such conditions one must take into considera-
tion not only the possibility of the brain becoming anemic, but also
the development of hypoxic phenomena of a congestive character if accel-
erations are continued for any length of time.
The results of the investigations showed that reflex reactions of
the neuromuscular apparatus of the larynx to accelerations are of
unusual interest. Although they are ordinarily not considered in the
complex of protective reflexes to accelerations, they exert a direct
regulatory effect on respiration and through it on hemodynamics. The
cortical nucleus of these reflexes is believed to be in the region of
the second and third frontal gyri. There is good reason to believe that
there are subcortical centers and that they are closely connected with
the motor analyzer.
Summary
The body's defense reactions to accelerations are complex reflexes
that participate in all of its functional systems.
Motor protective reflexes (increase in muscular activity, espe-
cially in the abdomen and chest (diaphragm) aimed at mechanical protec-
tion of the viscera) are particularly sharp. These reflexes are closely
connected with respiration, activity of the diaphragm, and muscles of
the larynx and chest during accelerations, and they result in involun-
tary, sustained expansion of the lungs and cyclical resistance to exha-
lation .
The aforementioned protective reflexes and related pressor-vascu-
lar reactions appear earlier than the vascular reflexes from the recep-
tor zones of the blood vessels, thus aiding the body when exposed to
accelerations .
An important aspect of hemodynamics during accelerations may be the
slowing of blood circulation, which after prolonged exposure may result
in hypoxia.
100
IWOLVEMENT OF THE VESTIBULAR APPARATUS IN REGULATING
THE BLOOD SUGAR LEVEL
E. Kh. Gambarova
Investigations on animals and human beings show that during space
flights changes take place not only in various organs and systems, but
in the vestibular apparatus as well. The vestibular apparatus which
plays a major role in coordinating movements and spatial orientation,
is also involved in autonomic functions.
To determine the degree and nature of involvement of the vestibu-
lar apparatus in regulating the blood sugar level, we performed the
following series of experiments:
Series I - Study of change in blood sugar before and after rotat-
ing rabbits in a Barany chair (with the same rate of rotations and
different duration of rotation) .
(a) Rotation at the rate of 10 rotations in 20 seconds.
(b) Rotation at the rate of 10 rotations in 15 seconds.
(c) Rotation at the rate of 10 rotations in 10 seconds.
(d) Rotation at the rate of 10 rotations in 5 seconds.
Series II - Study of change in blood sugar before and after rotat-
ing rabbits in a Barany chair (with a different rate of rotations and
identical duration of rotation) .
(a) Rotation at the rate of 20 rotations in 20 seconds.
(b) Rotation at the rate of 15 rotations in 20 seconds.
(c) Rotation at the rate of 10 rotations in 20 seconds.
(d) Rotation at the rate of 5 rotations in 20 seconds.
Series III - Study of the significance of the functional state
altered by drugs (bromides, caffeine) on the nature of reflex influ-
ences from the vestibular apparatus on blood sugar.
Series IV - Study of change in blood sugar after rotating in a
Barany chair rabbits with vestibular apparatus destroyed by the method
of A. B. Tsypin and Yu. G. Grigor'yev . Blood was taken from the
auricular vein twice before rotation, then 5> 15* 30, and 60 minutes
101
later. The sugar content was determined by Fujita-Iwatake" s method.
The following conclusions emerged from the investigations:
(a) Stimulation of the vestibular apparatus with rotations at the
same frequency but with different duration of rotation changes the blood
sugar content.
(b) Stimulation of the vestibular apparatus with 10 rotations in
20 seconds, 10 rotations in 15 seconds, and 10 rotations in 10 seconds
increases the blood sugar content, but 10 rotations in 5 seconds de-
creases it.
(c) Depending on the number of rotations and the rate, the maxi-
mum increase or decrease in blood sugar content occurs at different
times.
(d) Stimulation of the vestibular apparatus with rotations at the
same frequency and identical duration of rotation likewise changes the
blood sugar content.
(e) Stimulation of the vestibular apparatus at the rate of 20
rotations in 20 seconds and 15 rotations in 20 seconds decreases the
blood sugar content, but 10 rotations in 20 seconds and 5 rotations in
20 seconds increase it.
(f) Depending on the number of rotations and the rate, the maxi-
mum increase in blood sugar content occurs with rotation at the rate of
20 rotations in 20 seconds and 15 rotations in 20 seconds by the 5"th
minute, but the maximum increase with rotation at the rate of 10 rota-
tions in 20 seconds occurs by the 15th minute and at the rate of 5
rotations in 20 seconds, by the 5th minute.
(g) Interoceptive metabolic reflexes from the vestibular appara-
tus change under the influence of caffeine and bromides.
(h) After administration of 20 mg/kg of caffeine, stimulation of
the vestibular apparatus by rotation on a Barany chair at the rate of
10 rotations in 20 seconds first increases, then sharply decreases the
blood sugar content, which returns to the original level by the end of
the control time.
(i) After administration of 5°0 mg/kg of a bromide, stimulation
of the vestibular apparatus by rotation on a Barany chair at the rate
of 10 rotations in 20 seconds slightly decreases the blood sugar content,
which returns to the original level by the end of the control time.
102
(j) Blood sugar increases after unilateral and bilateral de-
struction of the vestibular apparatus.
(k) Rotation of animals on a Barany chair with unilateral de-
struction of the vestibular apparatus at the rate of 10 rotations in 20
seconds decreases the blood sugar content, the maximum being reached
after 15 minutes. Under these experimental conditions, the original
blood sugar content is not restored after 60 minutes.
(l) Rotation of animals on a Barany chair with bilateral destruct-
ion the vestibular apparatus at the rate of 12 rotations in 20 seconds
has little effect on the blood sugar content.
(m) In the light of the foregoing, it is fair to assume that the
vestibular apparatus exerts an effect on the blood sugar content.
CHANGES IN THE BIOELECTRIC ACTIVITY OF DIFFERENT PARTS
OF THE BRAIN DURING EXPOSURE TO PROLONGED ACCELERATIONS
0. G. Gazenko, B. B. Yegorov, G. V. Izosimov, Yu. P. Limanskiy,
A. N. Rasumeyev, and P. M. Suvorov
Study of the nervous system's reaction to accelerations has great
practical significance for aviation and space medicine. The use of
electrophysiological mthods has made it possible to investigate the
dynamics of nervous system function both during and after accelera-
tions.
The general nature of the changes in bioelectric activity of the
cerebral cortex and some subcortical formations in response to accelera-
tions was described in the works of Jasper et al. (195&) , v - !• Babush-
kina et al. (1955), Sam-Yakobsen (1959), Edie and French (1962) , and
others. However, the nervous mechanisms of these disturbances have not
yet been elucidated.
After analyzing the data on the functional state of the higher
divisions of the CNS in man and animals, we tried to uncover the various
mechanisms governing the interaction of different parts of the brain
in response to accelerations. In investigations of 118 healthy young
persons--using an ink-writing EEG, with mono and bipolar leads--we
studied the bioelectric activity of the frontal, parietal, and occipital
regions of the cerebral cortex. The accelerations were produced in a
centrifuge in a head-pelvis direction (intensity 3-7 units) and
103
back-chest direction (intensity 7-12 units) , the duration of action
ranging from 30 seconds to 3 minutes.
The changes in bioelectric activity had many features in common
regardless of the direction of the accelerations. The only difference
was in the time that the EEG reaction set in. With the head -pelvis
direction, this reaction appeared sooner and took place much more
quickly than with the back-chest direction.
The dynamics of these changes was characterized by a phase develop-
ment of the process, with P rhythms predominating at the start of acce-
leration. The ct rhythm, in some cases, became less distinct with eyes
closed than before the action, while its amplitude and index decreased.
We designated this shift toward desynchronization of the cortical bio-
potentials as the first phase: it usually occurred with axial radia-
tions of 3 - ^ units and lateral accelerations of 5-8 units. As the ac-
tion continued, the amplitude and index of the CL rhythm with eyes closed
increased against a background of rapid oscillations. At this time some
of the subjects had distinct oscillations of the a rhythm even with eyes
open. This second phase of "exaltation of the a rhythm" followed axial
accelerations of 5-7 units and lateral accelerations of 8-10 units.
The amplitude of the a rhythm then decreased again, and the P rhythm
gradually disappeared. Slow 9 and A waves began to predominate on the
EEG. This phenomenon usually preceded visual disturbances, the appear-
ance of the so-called "gray shroud". Synchronization of the cortical
biopotentials characterized the third phase.
A comparison of the changes in the biopotentials with the simul-
taneously recorded value of arterial pressure (in the pinna) showed
them to be definitely related. The development of phase processes in
the cortex was accompanied by a gradual fall in arterial pressure.
The original picture of bioelectric activity was gradually restored
in the aftereffect period, with the amplitude of the a rhythm with
closed eyes decreasing as soon as the rotations ceased. The rapid fre-
quencies predominated at this time, but, after 1-3 minutes of exposure,
the a, rhythm with eyes closed became more pronounced than under normal
conditions, its amplitude likewise increasing. Bioelectric activity
usually became normal after 5~7 minutes.
The purpose of the experiments on animals was to find some common
patterns underlying the changes in bioelectric activity in different
parts of the brain after lateral accelerations. The general nature of
the changes in cortical biocurrents in relation to the intensity and
time of action was studied in 50 rabbits. The intensity ranged from
2 to Ik units. The rate of increase was constant-- 1 unit every 10
seconds. The cortical biopotentials were recorded in a bipolar lead
from the sensorimotor region. The rabbits exhibited phase changes in
104
cortical biopotentials during accelerations that resembled those ob-
served in humans. The first phase was marked by de synchronization
of the cortical biopotentials, decrease in amplitude, and simultaneous
shift toward the high frequencies. Later, against this background
appeared individual high-amplitude slow waves of 2-3 oscillations a
second, which became dominant fairly quickly. Thus, the second phase,
unlike the first, was characterized by a shift toward slow synchronous
oscillations. Cardiac disturbances (arrhythmia and extrasystole) and
marked slowing of the respiration rate developed against this back-
ground. We also distinguished a third phase of pronounced autonomic
changes in response to acceleration, occurring only after accelerations
of more than 6 units. After the accelerations were halted, the origi-
nal picture of bioelectric activity was gradually restored.
Our. later investigations were designed to study the reactions of
different brain formations. Accordingly, electrodes were first im-
planted in the sensorimotor cortex, posterior hypothalamus, and reticu-
lar formation of the midbrain, with intensity of acceleration ranging
from 3 to 7 units.
The experiments showed that during the first phase, when desyn-
chronization was noted in the cortex, synchronous oscillations of the
basic rhythm of 5-6 a second intensified in the reticular formation and
hypothalamus. Accelerations of about 7 units produced slow high-ampli-
tude waves in the cortex (second phase). At this time, slow high-
amplitude activity was also evident in the hypothalamus but there was
a decrease in the amplitude of the basic rhythm of 5-6 oscillations a
second in the reticular formation. Then a marked shift toward rapid
oscillations was noted in the potentials derived from the hypothalamus.
Activity completely disappeared at this time in the reticular formation
while slow waves predominated in the cortex. Continuation of the rota-
tions caused activity to disappear both in the cortex and in the hypo-
thalamus.
When rotation was halted, if the animal survived, bioelectric ac-
tivity was restored in these formations. In all cases there was first
restoration in the cortex, then in the hypothalamus and, finally, in the
reticular formation. A similar picture was also observed in oxygen star-
vation by V. B. Malkin, A. N. Razumeyev, and G. V. Izosimov.
Thus, of all the formations that we investigated, the most sensitive
(reactive) to accelerations was the reticular formation. The reason for
this may be its unusual sensitivity to an inadequate blood supply (Keti,
1956). On the other hand, since the rostral portion of the reticular
formation is a collector of afferent impulses en route to the cortex,
it can develop into a focus of protective inhibition as a result of an
"avalanche" of impulses arising from the mechanical action of accelera-
tions on the various receptors of the body.
105
To clarify these mechanisms, special micro-electrode investigations
of cell units of the brainstem reticular formation were carried out on
cats anesthetized with chloralose. A total of 100 cell units was re-
corded.
From the very beginning of the accelerations, there was a signifi-
cant increase in the frequency of the spike activity of the neurons.
With simultaneous recording of 2-3 neurons, one could see that their
activity was nonsynchronous. Then, as the action continued, the group-
ing of spikes was recorded in individual bursts with periods of "silence".
The periods of silence gradually lengthened and the bursts became
shorter. The activity of the action potentials was synchronous when
they were derived from 2-3 neurons simultaneously. These changes coin-
cided in time with the appearance in the reticular formation of ordered
rhythms at a frequency of 5-6 oscillations a second. After 8O-85 sec-
onds, with accelerations of 5 units, activity of the cell elements
ceased entirely. In the restoration period these phenomena occurred in
reverse order. At first, bursts of cell activity appeared, after
which the rhythm of the neuron regained its original characteristics.
Hence, the fact that the start of changes in the reticular forma-
tion coincides with the time when acceleration causes virtually no
profound hemodynamic changes (beginning of rotation) suggests that the
afferent systems play a part in the mechanism of changes in nervous
activity. The stream of impulses flowing along the afferent pathways
may give rise to inhibition in the reticular formation. The resultant
inhibition presumably protects the cerebral cortex from the injurious
effect of the accelerations.
Our findings show that prolonged accelerations cause significant
changes in the bioelectric activity of different parts of the brain.
These changes are evident from the very beginning of the accelerations.
Research on the functional state of the CNS during accelerations
should be broadened to include the practical problems involved in pro-
tecting the organism from the injurious effect of space flight factors.
ANTICIPATING REACTIONS IN FLIGHT ACTIVITY
S. G. Gellershteyn \
1. Stimulus -and -reaction in the behaviorist interpretation does
not accurately reflect the true nature of the sensorimotor activity of
106
fliers. We find incontrovertible proof of this view in the results of
psychological analysis of the processes that characteristically take
place in critical situations, when time is short, and under conditions
of emotional stress.
2. The weakness of the materials describing flight activity lies
not in the lack of facts or analytical judgments apropos of these facts
but in the absence of a leading idea, the need of which is felt most
keenly when synthesizing the data and when trying to write up the inte-
gral characteristics of flying as an occupation and to reveal its psy-
chological nucleus.
3. Like any other complex occupation involving danger and possible
contact with acute and difficult situations, flying at certain times
requires high concentration of will and readiness and the ability to
withstand factors that subject the nervous system to arduous trials and
prolonged stress.
k-. To understand the processes that take place in these situa-
tions, one must contrast the stimulus -and -reaction concept with a
psychological concept that would reflect the true relations among the
sensory, intellectual, and motor components of flying.
5. It seems that this concept should be based on a dynamic under-
standing of the sensorimotor complex in the light of which all the in-
fluences impinging on the sensory sphere would be regarded not as stim-
uli following one another but as a stream consisting at each moment
of traces of past and precursors of future influences. In any given
field of consciousness always there are elements of the past, present,
and future fused together by the problem confronting the flier. A
stimulus in the strict meaning of the word is an arbitrary term when
applied to a genuine flight situation at critical moments. In each
unit of time the external influence combines with traces of apparently
forgotten processes and, even more important, with the "embryos" of
those actions that seem to be stored up for events that have not occur-
red but which are expected.
6. It is in this connection that we have a right to speak of the
role of anticipating processes in flying. Anticipation should be re-
garded as a means of orientation toward the predictable future. There
is a genuine process of anticipation based on knowledge or recognition
of the logic of the development of events. Just as a situation develop-
ing in flight generally contains the seed of a future situation, so does
the seed of a future action mature in the mental activiity of a flier
at each moment. "Stimulus and reaction" constitutes a long drawn-out
phenomenon that embraces that which was, is, and will be.
107
7. Anticipation becomes possible owing to the latent reaction of
expectation, which is rightly called the adjusting reaction. It
attunes the flier to certain actions when there seems to be as yet no
reason for them. It apparently prepares and shapes, these actions,
forming their initial latent phase. If the expected events occur, the
flier, thanks to anticipation, is, better prepared to cope with them, and
his actions are not only sounder but quicker --even under clear-cut con-
ditions of time shortage.
8. It would be inexcusable if, convinced as we are of the enormous
significance of anticipating processes in flight activity, we failed to
take steps to confirm it experimentally for possible use in dealing with
the selection and training of personnel and control of accidents. Our
past experiments, though scarcely complete, sometimes enabled us to
come close to experimental modeling of the anticipating processes, but,
unfortunately, we only came close. Now more than ever it is time for
us to return to the problem and seek an adequate experimental solution
through a direct attack.
DATA ON THE BEHAVIOR AND SOME FUNCTIONS OF PERSONS KEPT
UNDER THE CONDITIONS OF LIMITED MOBILITY
M. A. Gerd
The normal functioning of the human organism as it evolved over
a long period of time is dependent on motor activity of various kinds
and degrees, periodicity, etc. Human motor activity can be safely
restricted up to limits that are still uncertain to us. Restricting
mobility beyond these limits is apparently harmful to man.
On space flights human beings will in all likelihood be in situa-
tions where their activity will have to be based on some restriction of
mobility. The astronauts in the cabin of the Vostoks were lying down
(mostly on their back) and their activities did not require much active
movement, strength, speed, or static exertions. Moreover, in weightless-
ness, movements are made without the ordinary resistance that develops
when the body is shifted under the influence of gravity and they do not
place the load on the organism that they do under terrestrial condi-
tions. Consequently, it will be possible to speak of phenomena of
immobility in weightlessness despite the many actual movements.
108
All this indicates that the effect of limited mobility on the
body is a major scientific problem in space research. First things to
be considered here are the possible degrees of immobility, permissible
duration, and how the phenomenon is perceived by the persons themselves.
They have both practical significance in the organization of space
flights and theoretical significance in studying movements as a biolo-
gical necessity. Appropriate investigations were undertaken to throw
some light on these questions.
A total of 12 experiments lasting 2, 5, 7, and 10 days were con-
ducted. The subjects --healthy persons 20-22 years of age--were placed
in an arm chair that simulated in angular parameters the working place
of a astronaut on board a Vostok. To obtain maximum immobility, the
subjects were instructed not to move, and a locking device was used to
ensure this. They were in a semi -reclining position, head raised, legs
partly bent at the hips and knees --a position of maximum muscular re-
laxation in which muscular fatigue is very slow to develop.
The techniques used to study motor activity and behavior included
recording of movements, time study, recording of actograms (by Ye. I.
Lavrenchik) . During the experiments the Mede device with recordings
(as modified by Komotskiy, Gerd, and Ferov) was used to measure the
precision and direction of movements, nature of deviations (upward,
downward, to the right, to the left), "duration of deviations, change
in characteristics of static exertions of the arm. The speed of
simple motor reactions was recorded by the apparatus. A study was also
made of the correlation of the processes of excitation and inhibition in
the CWS. There were daily inquiries and observations in accordance with
a specially prepared program.
The results show that motor behavior, mental state, and several
physical functions changed considerably in 10 out of the 12 subjects.
Analysis revealed that the changes, despite the variety of forms,
fell into general patterns with characteristic features and 5 separate
periods. Individual features were manifested in, (a) the nature of
the phenomena and time they arose, (b) the fact that the periods were
long drawn out in some subjects but short in others, (c) the differences
in intensity of the motor reactions, and (d) subjective sensations.
First period (l-5 hours) - characterized by the fact that the sub-
jects admitted that the position assumed was maximally comfortable with
little desire to move. The time study and actogram indicated the sub-
jects easily conformed to the requirement of the experiment --to lie
still.
109
Second period (it lasted a day in some subjects, up to 6 days
in others)— characterized by increasing desire to change position,
stretch the legs, stand up, begin to move vigorously. In. 9 out of the
10 subjects these desires became clearly pronounced, and the impossi-
bility of satisfying them made k persons somewhat irritable and slightly
apathetic. Unusual kinds of movements began to appear, without obvious
shifting of the extremities and trunk- -scarcely perceptible stretching,
exertion of various groups of muscles, supination of shoulder and fore-
arm muscles, twitching, feeling of heaviness. Three subjects felt sharp
pain when they first tried to tense their arm muscles.
The initial site of the disagreeable sensations throughout this
period was followed by irradiation of the pain; some persons developed
a general sensation of fatigue. The time study and actogram showed
a sharp increase (up to threefold) in the number and intensity of
barely perceptible movements. Judging by the arithmetic means, the
precision of the movements decreased even more (0.5 to 2-fold), their
rate slowed (by 2 to 6 hundredths of a second), and hand tremor in-
creased (1.5 to 2-fold). Seven of the 10 subjects became more apa-
thetic: 3 reacted sluggishly to people and other stimuli, while k, on
the other hand, although depressed, demanded constant attention, be-
came loquacious and quick to take offense.
Fourth period 1 - characterized by increasing pain. Some first
became aware of it within 5 hours of the start of the experiment,
others - only on the 3rd or 4th day. Pain developed in the lumbar
region, gastrocnemius muscles, and muscles of the posterior part of the
femur. All had pain in the knee joints.
At first the sensations were transient and mingled with fatigue,
followed by sensations of heaviness and itchiness. The pain, as a
rule, was in one or two places. However, in most subjects the pain
became more pronounced and widespread. In two, it "crawled" all over
the body.
The time study data showed that in some subjects the number of
movements at this time sharply decreased, but increased in others.
However, the desire to move and to stand up became overwhelming.
Emotional changes were marked by a considerable poverty of mental
reactions. The subjects lay quietly, answered questions in mono-
syllables, turned away from people, and scarcely reacted to stimuli
1
Tr. Note: The author does not mention the third period.
inn
no
(3 subjects). Four subjects in a melancholy mood had a strong desire
to come in contact with the attendants, to chat, to be in a situation
with changing impressions. Almost all had a very poor appetite. Signs
of euphoria appeared only when the planned end of the experiment drew
near.
Changes in the volitional sphere were manifested in the difficulty
with which some subjects performed the assigned tasks. Elements of
weak negativism were observed in 3 persons. The methods used to inves-
tigate mental alertness (arithmetic problems, etc.) showed some slowing
of the intellectual processes, despite complete retention of the higher
mental functions.
Based on measurements of the latent period after differentiations
and of the time of the "behind" reflex, it is reasonable to conclude
that in most of the subjects immobilization gave rise to changes in the
direction of a predominance of the processes of inhibition.
Fifth period (observed in 3 subjects at the end of 7 "to 10 day
experiments) --characterized by progressive weakening of negative sen-
sations. Pain and fatigue disappeared and the urge to move was no
longer acute.
Time study data and actograms showed a reduction in the number
of movements made during this period. Almost all the subjects had the
Urge to stand up and to change postion; there was tense expectation of
the end of the experiment, producing in most either an improvement in
mental state or mild euphoria.
As soon as the experiment ended, and for 1-3 hours thereafter, the
subjects felt weak and dizzy and had difficulty in moving. There was
a sharp deterioration in motor and static characteristics and a slowing
of the speed of movements. Such phenomena as unsteady gait, weakness,
and sluggishness persisted for 2-3 days. All this underlines the need
of movement as a prime biological requirement.
On the basis of our findings, it would seem that the degree of
immobilization used in our experiments is close to the limits of what
man can tolerate, although the actual limits are not yet known. Immo-
bilization can continue for more than 10 days without prolonged after-
effects and complete restoration of all functions in 2-k days.
The theoretical basis of the biological need of movement is as
follows. Prolonged immobilization evidently causes changes in normal
biochemistry in the trophism of muscular tissue and nature of its
proprioceptive impulses, and, as a result, in other unconditoned and
conditioned reflex innervation of the muscles. The need of movement
apparently enables the body to manage the load essential for its normal
I II I III! Ill II II I
Ill
f unctioning . An indication of this, as shown by our experiments, was
the increasing desire of the subjects to move.
The contrast between the need of movement and the possibility of
satisfying this need apparently gave rise, on the one hand, to various
disagreeable sensations (starting with local fatigue and ending in
pain) and, on the other, to persistent movements that did not involve
shifting of the extremities or trunk. These reactions could compensate
only partially for the lack of a motor load, giving rise to increasingly
disagreeable subjective sensations and change in mental state the longer
the immobilization lasted.
It is a well-known fact that such phenomena as depression, mild
apathy, and poor frame of mind often cause general motor sluggishness.
Our findings suggest the possibility that the reverse relationship
exists too, i.e., immobilization combined with relatively limited ex-
ternal information may result in depression and inhibition.
THE PHYSIOLOGICAL-SANITARY JUSTIFICATION FOR SUBSTITUTING
A LUMINOUS SUBSTANCE OF INTERMITTENT ACTION FOR
THE PHOSPHOR NOW USED ON AIRPLANE INSTRUMENT DIALS
V. Ya. Gilinskiy and A. Ya. Loshak
The main criterion of a pilot's fitness for independent flight,
especially in foul weather, is his ability to fly by instruments. He
must therefore be able to see instantly and evaluate the readings of
the individual instruments, determine the position of various switches,
etc. The dials are painted with a luminous substance of constant ac-
tion, a source of gamma radiation. It is intense enough, according to
our data, to make an important contribution to the total dose of ex-
ternal radiation received by the personnel, especially on gas-turbine
aircraft. We therefore thought it necessary to determine whether the
radioactive paint could be replaced by some other substance of inter-
mittent action which, though lacking in radioactivity, would ensure
adequate visibility. We also thought it worthwhile to determine the
best color for the paint and lighting system of the instrument panel.
Accordingly, we made 7 flights on a LI-2 and Ik flights on a TU-10U
using experimental instrument panels with a luminous substance of
intermittent action and making appropriate physiological- sanitary in-
vestigations. The program called for the following:
112
(a) Determination of the effectiveness of the lighting system of
the instrument panel, control panel, etc., involving the use of sub-
stances with zinc or cadmium sulfide irradiated by UFO armatures.
(b) Determination of the relationship between the brightness of
the instrument dials during flights at twilight and at night and
physiological requirements.
(c) Determination of the level of eye adaptation and readaptation
in pilots during long flights and near airports.
(d) Determination of the electric sensitivity of the eye.
(e) Determination of the pilot's problem when masking shroud or
blue fog appears in the cockpit.
(f) Determination of the possibility of distinguishing warning
signs on instruments.
(g) Determination of the amount of radiation emanating from the
instrument panel .
(h) Determination of the radiation level in airplane cabins.
(i) Conducting individual monitoring of the crew.
(j) Determination (on the basis of the available data) of the
degree of fatigue resulting from flying by instruments painted with the
tested luminous substances, followed by a comparison of the data and
then checking them against the results obtained by using a substance of
constant action.
During the flights, besides obtaining subjective data, we used a
variety of methods previously approved for scientific and practical
investigations in aviation medicine.
Our investigations were carried out:
(a) With FK-102 orange -colored cadmium and FKP-03K green-colored
zinc sulfide.
(b) At different times of the day (in daylight, at twilight, at
night) and under different meteorological conditons.
(c) At all stages of the flight and near airports.
(d) With lighting systems for landing turned on in full or in part.
(e) While using an ARUFOSh-V? or ARUFOSh-50 armature with different
ways of regulating the bias lighting sector.
(f) Before, during, and after flights.
(g) During night flights over well -illuminated inhabited localities.
The results of the investigations showed that in the passenger com-
partments the levels of radioactive radiation do not exceed the back-
ground characteristic of the altitudes at which the measurements were
made. The dose rates of gamma radiation (mr/hour) recorded on the
113
surface of aviation instruments, in the working places of the first
and second pilots, and at different spots in the crew compartment (with
use made of a luminous substance of intermittent action, 65 hours a
month sanitary rate of deposit, and 10-month work year) were one-half
to one -third the maximum permissible level.
The results of an investigation of higher nervous activity,
various functions of the visual analyzer, perception and evaluation of
readings of aviation instruments, degree of fatigue of flight personnel,
etc., revealed that insignificant physiological changes (within the
limits of ordinary functional changes) appeared in bodily functions
after 4-hour flights with the experimental system of instrument -pane}
illumination. Similar results were obtained in an investigation of
flight personnel when a luminous substance of constant action was used.
It appears that the green color is best, as demonstrated in the
processes of eye adaptation and readaptation, electric sensitivity
of the eye, shortening of the afterimage and lengthening of the latent
period. The degree of change in these indices was 15-25 percent. The
use of green paint also improves the conditions for reading the dials
of instruments and makes it easier to distinguish between warning signs.
The conclusions of our investigations are as follows:
(a) Instrument panels painted with a luminous substance of
constant action should be changed owing to the relatively high radio-
activity.
(b) Lighting instrument panels with luminous substances of inter-
mittent action irradiated by UFO armatures is effective.
(c) Of the two types of instrument panel lighting, the more use-
ful is the FKP-03K green-colored zinc sulfide.
THE EFFECT OF LOW CONCENTRATIONS OF CARBON MONOXIDE ON MAN IN
PRESSURIZED CABINS OF PASSENGER PLANES
V. A. Gilinskiy, A. V. Chapek, A. G. Kozlova,
N. M. Kulikova and A. Ya. Loshak
The human organism in general and during flight in particular re-
quires careful observance of certain environmental conditons, i.e.,
the so-called comfort conditons that make it possible for a flier to
live and remain fit with minimal fatigue during flight.
11U
Many authors (A. A. Letavet, E. E. Grigor'yev, L. S. Gorsheleva,
I. I. Datsenko, and others) have concluded that prolonged exposure to
low concentrations of carbon monoxide may adversely affect health by
causing chronic carbon monoxide poisoning.
We found no references in the available Soviet or foreign litera-
ture to carbon monoxide effect on human beings in pressurized cabins
exposed for 3 hours to maximum permissible concentrations and to low-
concentrations under ground conditions (pressure -chamber experiment) and
at altitudes of 8000-10,000 meters.
There is as yet no consensus either in international practice or
in the Soviet Union on the maximum permissible concentration of carbon
monoxide in pressurized airplane cabins. The specialized literature
contains no data that confirm the soundness of applying the maximum per-
missible CO concentration (0.02 mg/liter) established for ground condi-
tions to the conditions of low partial pressure of oxygen in inhaled
air.
We performed pressure -chamber experiments on 82 persons to study
the effect of low concentrations of carbon monoxide. We also made 30
flights on IL-l8, AN -10, and TU-104 planes during which we examined 185
members of the crew and passengers and studied 3^7 air samples obtained
in the cabins.
The results of the investigations showed that 3 hours' exposure to
carbon monoxide (starting with 0.01 mg/liter or more), both under ex-
perimental conditions (ground and pressure -chamber at 2400 m) and during
actual flight had adverse effects on the functioning of several organs
and systems, namely:
(a) Higher nervous activity (manifested in a breakdown of dif-
ferentiations; deterioration of memory, capacity and concentration of
attention; increase in amount of time required for a proof-reading test,
etc. ) .
(b) Functions of the visual and vestibular analyzers (increase in
latent period and decrease in duration of the after-image, shortening
of the time of illusion of counter-rotation, etc.).
(c) Metabolic processes (change in bodily temperature).
(d) Cardiovascular system (change in arterial pressure, oscilla-
tory index, change in myocardial function, etc.).
(e) Muscular strength (decrease in indices of manual dynamometry) .
115
(f) Tissue respiration (formation of carboxyhemoglobin in the
blood ) .
(g) Leukopoiesis (change in composition and formed elements of
the blood).
On the basis of the physiological -sanitary data obtained and the
results of laboratory tests, it is suggested that the maximum permissi-
ble concentration of carbon monoxide in pressurized passenger airplane
cabins be 0.01 mg/liter.
MORPHOLOGICAL CHANGES IN THE NERVOUS SYSTEM OF ANIMALS
SUBJECTED TO LATERAL ACCELERATIONS
B. S. Glushkov
Although much material on the subject has been gathered in the past
20 years, continued study of morphological changes arising in the ner-
vous system after exposure to accelerations is of value in clarifying
the reasons for impairment of various functions caused by acceleration.
Unfortunately, morphological data are meager.
This report presents preliminary findings on morphological changes
in various divisions of the nervous system of animals subjected to sin-
gle lateral accelerations of varying intensity and duration. Experi-
ments were performed on 7 rabbits, with accelerations ranging from k.9
to 5.9 g produced in a centrifuge with lateral (back-chest) orienta-
tion of the animals in the direction of the centrifugal force. The
action lasted from 60 to l80 seconds. The animals were kept under ob-
servation from 1 to 7 days after the experiment.
The following were used for histological investigation: the entire
brain, two fragments from each section of the spinal cord with the inter-
vertebral ganglia, both nodose ganglia of the vagus nerves, both super-
ior cervical sympathetic ganglia, semilunar ganglia, thoracic sympathetic
chain, celiac ganglia, and some viscera (heart, lungs, esophagus, stomach,
major blood vessels). All material was treated by the methods of Nissl,
Van Gieson, Marchi, Mallory, Bielschowsky-Gros, Cajal in Ranson's and
Favorskiy's modifications, and with hematoxylin-eosin.
Hemorrhages of varying severity were found in the brains of k
rabbits - from small extravasates to a large subcortical focus in
rabbit No. 2 (5-2 g.- 180 seconds). All animals showed spinal cord
116
hemorrhages concentrated, for the most part, in the gray substance,
chiefly in the thoracic and lumbar segments, in the nature of small peri-
vascular foci.
Perivascular edema was noted in all cases. When stained by Nissl's
method, the most distinct but generally reversible changes in nerve
cells were found in the cerebral cortex (chiefly in layers 2 and 3) and
hippocampus. These changes represented various phases of chromatolysis
of Nissl substance, frequent vacuolation of nerve cells and, at times,
"severe disease" of the latter.
Changes in the nerve cells of the intervertebral and other sen-
sory and autonomic ganglia were insignificant, consisting mainly in a
redistribution of Nissl substance in the cell body - in a coarsening
or dispersion of the substance.
The nature of the morphological changes caused by lateral acce-
leration which seem to be reversible, suggests they are the result of
marked disorders of blood circulation in the CNS.
SOME FUNCTIONAL CHANGES IN MAN AFTER PROLONGED ISOLATION
F. D. Gorbov, V. I. Myasnikov, and V. I. Razdovskiy
The increasing pace of automation of industrial processes is mak-
ing essential the early and discriminating determination of stress and
fatigue. The problem assumes greater urgency in cases where the
factor of continuous work is combined with spatial shifting of man
with the object, e.g., in various types of transport, aviation, and,
above all, in spacecraft (V. I. Yazdovskiy, 1962) .
In 18 experiments, the subjects spent 10-15 consecutive days
in a small, enclosed space in a specially equipped chamber. The main
condition of the experiment - isolation - was ensured by solitude, lack
of two-way oral communication, and practically complete isolation from
outside light, sound, or other stimuli. One-way communication from
subject to experimenter was limited by the program and transmission
time.
The subjects' functional state was evaluated in various ways:
observation of behavior and emotional reactions; the dynamics of bio-
electric activity in the cerebral cortex ; determination of the speed
of motor reactions; and psychological exercises (tests for "noise
^
117
immunity" were devised by F. D. Gorbov and L. D. Chaynova) combined
with data derived from observation and recording of vocal reactions
on magnetic tape.
Analysis of data showed that functional change began before the
experiment started, continued throughout the experiment, and lasted for
some time after it was over. Each stage had its own peculiarities.
During the preparation for the experiment the subjects exhibited some
tension, reflected in slight agitation with appropriate change in facial
expression, vocal intonation, etc. These phenomena were observed in
some subjects after 1 or 2 days of isolation. In cases where signs of
stress were very pronounced, the EEG showed an indistinct a, rhythm
against a "background" of p activity while the index of the a rhythm
dropped 8-40 percent below the original level. In recording the
motor reaction, we observed a spread in the indices of the latent
period and spontaneous fluctuations of the cutaneogalvanic reflex. In-
vestigations of "noise immunity" were accompanied by the appearance of
errors at the start and in the middle of the work.
Biochemical findings also testified to the development of emo-
tional stress at this time. For example, there was an increased excre-
tion of urinary 17-ketosteroids, the highest level being noted on the
2nd -3rd day of isolation, i.e., when fatigue could not yet have been
fully manifested. It is noteworthy that in the control experiments,
when the subjects were in the chamber under the same conditions, includ-
ing diet, but could communicate freely with the outside world, there was
no increase in urinary 17-ketosteroids (Yu. F. Udalov) . Emotional
stress during the preparation period and first days of the experiment
were regarded as analogous to the pre-starting state based on inadequate
preliminary adaptation of the subjects to the experimental conditions.
The emotional stress was a wholly adequate reaction and was not accom-
panied by important deviations in accomplishing the experimental psy-
chological tests and tasks. These changes, which imply some modifica-
tion in the body's functional state, can be regarded to a certain extent
as a standard of stress since there was no question of fatigue at this
time.
The subjects began to experience fatigue after the 6th-7th (8th)
day. They felt also, the need of conversing, of communicating with
the experimenter, as shown by the construction of reports in interroga-
tive form and inclusion in the reports of "extra" words and expressions
not called for by the instructions or bearing directly on the experiment.
At the same time there were 20 to 30 -minute periods when the subjects
were motionless and outwardly apathetic. Prolonged isolation caused
marked changes in the bioelectric activity of the cerebral cortex:
EEGs recorded at this time showed a decrease in the amplitude of the bio-
potentials, appearance of diffuse slow waves on the original EEG curve
Illliiiiiniii inmiii
118
(before the presentation of light as a stimulus), and a lowering of
cortical reactivity and excitability. Fairly significant changes were
noted in the degree and duration of exaltation of the a rhythm follow-
ing exposure to light. For example, in those persons who from observa-
tion and self -evaluation, seemed to be fatigued, exaltation of the a
rhythm after exposure to light became longer and longer until by the end
of the experiment it was stagnant and incapable of being reversed
(V. I. Myasnikov, 1963).
Investigation of the motor response showed a statistically signifi-
cant lengthening of the latent period of the reaction at the end of the
experiment (by an average of 120 milliseconds) . This increase was pro-
bably caused by fatigue, the first signs of which appeared simulta-
neously with the development of inhibition in the CNS (according to the
EEG data) . Study of "noise immunity" showed that the "level of the
assigned activity" decreased during the second half of the experiment.
Analysis of the results of handling the numerical table showed consi-
derable "disinhibition of differentiations" both in calculation and in
correct designation of the answer (a black figure was shown instead
of a red one and vice versa). In doing so the subjects exhibited a
tense attitude, engaged in mimicry, and made a great many searching
movements. The middle stage of the work with the black-and-red table
was the most difficult with respect to differentiation because the nu-
merical difference between the figures in the black and red rows de-
creased to unity even where there was a sharp increase in the number of
similar stimuli through repetition of 1, 2, and 3 (F. D. Gorbov, i960) .
Investigation of "noise immunity" at the end of the experiment was
accompanied by an increase in the total amount of time spent on the
numerical table .
Excretion of urinary 17-ketosteroids decreased when subjects
showed pronounced signs of fatigue. According to N. N. Sirotinin
(i960), a decrease in the excretion of 17-ketosteroids is an unfavora-
ble indication, signifying the organism's low tolerance of adverse con-
ditions. The protracted change and limitation of afferent impulses,
in the experiments with isolation, was a new and unusual stimulus that
resulted in complex mental and physiological changes followed by the
onset of fatigue.
Our investigations showed that a drastic limitation of general
afferent impulses had a significant effect on the subject. The changes
in psychoneurologic function varied at different stages of the investiga-
tions. Simultaneous recording of psychological and physiological indices
made it possible to ascertain the qualitative aspects of the changes and
to determine and delimit the state of tension and fatigue. The condi-
tions and causes of the development of stress and fatigue were the
monotony of the surroundings, poverty of external impressions, and
solitude --all factors of independent significance. These states can
119
and must be prevented by effective stimulation to promote the optimum
interaction of the afferent systems.
THE MAIN PROBLEMS IN INVESTIGATING SHOCK OVERLOADS ARISING
IN FLIGHTS ON AIRPLANES
S. A. Gozulov and G. P. Mirolyubov
The present stage in the evolution of aircraft and space flights
demands better methods of enabling the crews to land safely. Catapult-
ing followed by a parachute landing is often made more difficult by
unfavorable conditons (rough, stony ground, strong winds, etc.) or
the climatic and geographic characteristics of the area (arctic,
desert, sea, etc.).
Many safety problems in landing, after enforced abandonment of
the craft, are resolved by the use of a pressurized separable cabin or
capsule which the pilot can land. Physiological investigations of ani-
mal (dogs, white rats, mice) tolerance of shock overloads in landing
have shown that the boundary lines beyond which functional disorders and
morphological injuries arise in the organism are separated by a slight
overload and that under certain conditions they close together. In
the latter case, the functional disorders are accompanied by microsco-
pic injuries to individual tissues and organs, apparently secondary
reactions to the action.
Physiological reactions to shock overloads at high landing speeds
are characterized by impairment of the rate and depth of respiration
up to complete standstill, disruption of the cardiac rate and change
in the EKG indices, change in arterial pressure, impairment of muscular
excitability, and other phenomena.
Marked changes can be observed in the gross morphological and
histological picture when the animals are dissected after the event.
Since the degree of injury varies with the consistency and relative
position of the organs, the frequency with which a given organ is in-
jured varies from animal to animal. In all animals, the lungs are the
most frequently injured, then the liver, spleen, and intestine, in this
order. The nature and site of the hemorrhages throw light on some as-
pects of the mechanism of injury to the viscera. Specifically, lung
injury is caused largely by the pressure wave that arises in the ab-
dominal cavity and passes through the diaphragm into the thoracic
120
cavity. An important factor in the damage is the fact that dense organs
(heart and lungs) are near one another.
According to the data of foreign authors, a speed of 3 to 9 m/sec
is the optimum for landing from the engineering standpoint. Since this
may produce intolerable shock for the organism, it is essential to use
shock -absorbing devices. However, in emergency situations or when land-
ing on other planets, the impact of landing may be 10 times greater than
under ordinary conditions, and special protective measures are needed if
injury is to be prevented. Experiments on animals have shown that im-
mersion in a liquid and other methods may significantly reduce the land-
ing impact. For example, the use of a gypsum bed permits safe landing
on hard ground at a speed of Ik m/sec, which results in an impact of
1000 units. Further research in this field is urgently needed.
Another equally important matter requiring experimental investiga-
tion is human resistance to shock overloads lasting longer than the
shock of catapulting. The need to save the crew of a spaceship in an
emergency situation or to remove the pilot from the zone of fire of a
rocket engine accounts for the practical importance of research on the
effect of prolonged overloads in these situations. Experiments have
made possible the construction of safety devices for the Vostok, and
have thrown light on some specific characteristics of prolonged over-
loads (the evaluation of which requires a new approach), and on some
parameters of overloads previously disregarded or unknown.
To investigate the effect of the aforementioned overloads on man,
it is essential to develop and use techniques for early diagnosis of
disorders which indicate the limit of physiological endurance of impacts.
It is equally important to investigate the biodynamic reactions of the
body to shock overloads. Theoretical considerations have confirmed the
idea derived from experimental investigations that the correlation be-
tween the period of the natural frequency of bodily oscillations, dura-
tion of overload and rate of increase thereof plays a major role. The
duration of an overload and rate of increase were taken into account by
investigators as factors (on a level with intensity of the overload) in-
fluencing resistance, but the effect of the frequency characteristics
of the body were disregarded. This was probably due not so much to
neglect as to the practical difficulties involved in measurement and
instability of the period of the natural frequency of bodily oscilla-
tions. The latter changes with the position of the body, degree to
which it may be held fast by straps, muscular tension, etc. Study of
the relationship between resistance to shock overloads and correlation
of the aforementioned three values gives investigators still another
criterion for evaluating a factor of practical importance.
Further study of shock overloads with different parameters and their
mechanism of action on the organism and the development of methods of
121
resistance to such factors will help to ensure the safety of modern
aircraft and thus improve their tactical qualities.
INCREASING RESISTANCE TO OXYGEN DEFICIENCY BY MEANS OF DRUGS
G. I. Gurvich and K. S. Shadurskiy
One of the basic problems in aviation and space medicine is to en-
sure airplane and spaceship crews an adequate supply of oxygen. There
are two approaches to the problem: (a) development and perfection of
methods to provide individual oxygen supplies; (b) creating pressur-
ized cabins that maintain a certain partial pressure of oxygen. To-
gether, the two methods render flights safe either in the earth's
atmosphere or in outer space .
Of practical value, especially on long space flights, undoubtedly
will be the ability to decrease sensitivity to oxygen deficiency. In
recent decades various drugs have been proposed that are capable of in-
creasing in varying degrees bodily resistance to hypoxia. These are
mainly compounds that exert a tonic effect and compounds with an anes-
thetic, somnifacient action. Prolonged use of the first group, whose
effect is transient, results in exhaustion of the physiological reserves;
the second group impairs general efficiency. For these and other rea-
sons these drugs have not been used in aviation and space medicine.
Therefore, in our own efforts to find drugs capable of increasing re-
sistance to hypoxia, we focused on compounds with no unpleasant side ef-
fects (in the dosage used).
Our attention was drawn to the indole derivatives . We began with
the following: serotonin (5-hydroxytryptamine), iproniazid, BAS (l-
benzyl, 2. 5-dimethyl- serotonin), and compounds provisionally called in-
dole I, indole IV, and indole XXIX.
Rappoport, Green, and Page (19^9), Erspamer (1961), and others
have shown that serotonin is widespread in tissues and organs of animals,
and possesses high physiological activity. It is essential for the nor-
mal functioning of the CNS and other systems .
The effect of serotonin on resistance to oxygen deficiency was
studied in 19 guinea pigs, 20 rats, and 20 mice. All the animals in
these and subsequent experiments came from the same animal house and
they were of approximately the same age and weight. Ten guinea pigs, 10
rats, and 10 mice served as the control. The experimental animals were
122
injected intramuscularly with serotonin at the rate of 0.2 mg per kg of
body weight an hour before exposure to hypoxia. The control animals
were injected with physiological solution, which produced no visible ab-
normalities in the general behavior of the animals. Hypoxia was caused
by elevating the animals in a pressure chamber to an "altitude" of
11,000 m, at which the survival rate was studied.
The time of respiratory standstill- (in minutes) at an "altitude"
of 11,000 m in the animals that received serotonin and in the control
was :
Guinea pi
gs
White rats
White
mice
Control
Exp
erimental
Control
Experimental
Control
Experimental
8
7
0.2
1.8
3
2
9
12
o.i*.
2.1+
3
5
11
18
o.k
2.7
3
5 n
11
2k
0.5
3.2
k
60 1
12
28
0.5
3^
17
60
12
32
0.5
3-7
19
60
13
3^
0.6
5A
21
60
16
38
0.7
8.2
2k
60
2k
kl
0.8
9.0
26
60
2k
—
1.2
3-7
28
60
Ik
26
/IT. 3-H. 7/
/28
.3-23
.91
After being kept for an hour at the "altitude", the animals were
"lowered" and kept under observation for 2 weeks.
It is evident from the table that resistance to acute oxygen star-
vation was much higher in the experimental animals than in the control.
The amino compounds in the animal organism are known to undergo
constant oxidative deamination, and the enzyme monoaminoxidase plays an
important part in this process. In 1955 Weller et al. first demonstrat-
ed that iproniazid suppresses the activity of monoaminoxidase and pro-
motes the accumulation of serotonin. Our experiments on I50 white mice
showed that intraparietal injection of 100 mg/kg of iproniazid consider-
ably increases resistance to hypoxia. It is particularly effective when
injected 2, 3, k, 5> 6, or 7 days before exposure to hypoxia.
The results were processed statistically in all the experiments in which
the experimental animals survived at the "altitude" less than an hour.
123
Combined injection of iproniazid and serotonin in 120 mice showed
that the combination markedly lowers sensitivity to hypoxia, especially
when iproniazid is injected 2, 6, or 7 days before exposure.
BAS was administered orally for 5 days at the rate of 5 mg per g
of body weight to U0 rats and 100 mice. The experiments showed that
the very first day after the injection the life span of the experimental
animals at an "altitude" of 11,000 m was far above that of the control,
the difference being most pronounced at an "altitude" of 10,000 m. The
increased resistance of the experimental animals persisted for 10 days
after the injections were terminated.
In experiments on 120 rats, the effect of 5 days of injection of
5 mg/kg of BAS was studied 3, 6, and 9 days later. Resistance to hy-
poxia was most pronounced on the 6th and 9"th days .
The same dose was used on l8 guinea pigs, 10 of which served as
the control. The "altitudes" at which excitation was recorded and con-
vulsions developed in the experimental animals were much higher than in
the control. This difference was most pronounced on the 5th day after
injection.
The next group of experiments involved the use of indole I, indole
IV, and indole XXIX on lUO mice. The results showed that under certain
experimental conditions (selection of dose and time of injection) re-
sistance to hypoxia can be significantly increased.
Thus, our factual material suggests that it is very worthwhile to
look among the derivatives of indole and hydrazine for drugs to increase
resistance to oxygen deficiency.
WHITE RAT RESPIRATION AFTER PROLONGED EXPOSURE TO
RADIAL ACCELERATIONS
V. I. Danileyko, A. I. Nazarenko and 0. S. Savchenko
Acceleration affects the vital activity of the organism in a great
variety of ways. A very important index of the functional state- -the
degree of compensation of the changes that take place in the body--is
the intensity of gas exchange or level of its energy expenditure (V. I.
Babushkin, P. K. Isakov, et al., I958; P. K. Isakov, 1958).
121)-
The dynamics of these indices in human beings and animals subjected
to intense gravitation (the effect of acceleration and that of a gravi-
tational field are, of course, identical) have been studied by many in-
vestigators (L. Bjurlen, I938; G. Armstrong and D. Heim, 1938; others).
Influenced by the thought that functional changes are inevitable
in all three components of respiration (external respiration, transport
of oxygen by blood in the pulmonary circulation, tissue respiration),
we decided to try a somewhat different approach to the study of the
energy balance when the organism is subjected to a gravitation factor.
Consequently, we performed experiments on 25U white rats weighing from
102 to 160 g exposed to lateral accelerations in centrifuges with an
arm length of 65 and 256 cm.
The level of oxygen utilization was determined in 95 experiments
performed on 53 animals with the aid of a Krog apparatus. The tube
through which oxygen entered the hermetically sealed chamber (on the
centrifuge arm) with the animals during rotation was connected to the
apparatus by a movable adapter.
Carbon dioxide was absorbed by soda lime or KhPI placed in the
chamber with the animals . The respiration rate was investigated with
a carbon pickup secured to the animal's chest or with a piezo crystal
that transformed the respiratory oscillations of the air in the re-
spiratory system into electrical impulses amplified and fed into the
input of an N-700 oscillograph.
Blood circulation in the pulmonary circulation was evaluated by
gross inspection and, in a few cases, from microscopic examination of
lung specimens .
The intensity of brain tissue respiration was determined in a
Warburg apparatus .
The animal ' s body temperature was measured after the experiment
with a mercury thermometer or TEMP-60 electric thermometer.
Some of the animals were sacrificed so that we could measure the
temperature of the brain, liver, and kidneys . Liver temperature was
measured, in 10 animals, during acceleration.
In the experiments involving a large centrifuge, we found that the
rate of oxygen utilization by white rats exposed for many minutes to
lateral accelerations ranging from 2 to 30 units was higher than the
normal level. This fact fits in with the prevalent ideas on the general
biological mechanisms of gas exchange in living things subjected to in-
tense gravitation.
&
%
125
However, it is also well known that with a given level of action
varying from species to species, external respiration is suppressed.
For man and some animals (monkeys, dogs, etc.) 7-10 units constitute such
a limit, but the values are higher for animals with a small body mass
(in this case white rats). Our experiments showed a significant in-
crease in oxygen utilization even with accelerations of 17 units lasting
5 minutes.
Thus, the idea advanced by G. Galiley, K. E. Tsiolkovskiy, and
others that there is a relationship between the biological effect of
gravitational action and body mass of the individual has been confirmed
experimentally. One may speak of the specifically species character-
istics of the changes in gas exchange under these conditions.
We found marked individual fluctuations in oxygen utilization that
apparently varied with the reactivity of the organism, etc. With ac-
celerations of 5-17 units lasting for several minutes, the respiration
rate slowed only slightly.
The following data obtained in one of the series of experiments
are illustrative .
Oxygen utilization and respiration rate in a group of white rats dur-
ing experiments in a centrifuge (comparative values from 9 animals)
Before rotation
5 units,
5 minutes
10 units,
5 minutes
15 units,
5 minutes
After rotation
Oxygen utilization in 5 minutes
3^.0
80.7
99-9
I36.O
35-3
Respiration rate in 1 minute
123.4
95-6
89.3
9^.0
102A
The body temperature of the animals dropped by 3-8 after the ex-
periments, while the temperature of the viscera dropped by 3-5°.
Respiratory movements were markedly impaired in the animals that
died after 15 minutes of accelerations of 22-26 units. With accelera-
tions of 28 units, respiration became impaired in the first 2-3 minutes;
with accelerations of 50 units, in the first minute of the experiment.
Oxygen utilization increased even in cases where extensive
hemorrhages were found in the lungs of the animals sacrificed after
the experiment. After experiments in which white rats were exposed to
lateral accelerations of 50 units lasting 1-1/2 minutes, A. I.
Nazarenko found a statistically significant increase in oxygen
126
utilization by brain tissue. This increase is apparently due to com-
pensatory changes directed at liquidating the oxygen debt in brain tis-
sue and to intense afferent impulses from the displaced tissues and organs.
One author found that after prolonged intense gravitation the
animal's body temperature dropped sharply by 10 or more degrees with a
given value of the action (V. I. Danileyko, 1958, 1959, 196l, 1962) .
This phenomenon, called postgravitational hypothermia , depended only
to an insignificant extent on air cooling because it appeared even after
the animal was carefully insulated against heat. (The phenomenon of
postgravitational hypothermia in our experiments was accompanied by an
increase in oxygen utilization.)
The drop in temperature measured in the rectum and viscera occur-
red simultaneously except that the temperature of the viscera under
these conditions, as in the natural state, was always a little higher
than the temperature of the surface tissues and rectum.
It follows from the foregoing data that the respiratory function
in an organism exposed to intense gravitation and its energy expenditure
change in all the components of respiration.
This work is the first part of an investigation into the nature of
these changes and the relations among them since they are fairly com-
plete reflections of changes in the general state of the- organism. The
organism's tdlerance of gravitation would be increased if they were
prevented .
IMPAIRMENT OF THE MECHANISM OF MITOSIS IN MICROSPORES
AFTER FLIGHT ON V0ST0K 3 AND V0ST0K k
N. L. Delone, P. R. Popovich, V. V. Antipov,
and V. G. Vysotskiy
The main categories of hereditary changes are: (l) gene (point)
mutations; (2) structural rearrangements of chromosomes; (3) mutations
of genomes resulting in polyploidy; (k) nonbreakage of chromosomes re-
sulting in the appearance of hyperploids and aneuploids.
Although Tradescantia microspores are of no value in studying the
first type of mutations, they are an ideal object for analyzing chromo-
some rearrangements. They can also be used in analyzing the third and
fourth categories of mutations. It is possible to analyze figures with
'%
127
impaired mitoses (while studying one cycle of cell division during
which some action was carried out) and thus trace the first stages in
the development of polyploid and other forms. N. P. Dubinin observed
primary nonbreakage of chromosomes in Drosophila exposed to space flight
factors on sputniks .
Tradescantia paludosa microspores and analysis of the specimens
by the acetocarmine method have been described by us elsewhere. Cut
Tradescantia stems with inflorescences were placed in special holders
on Vostok 3 and Vostok h. The experiment on Vostok k was performed by
astronaut P. R. Popovich who fixed the material during the 37th orbit,
i.e., 56 hours after the launching. We analyzed the metaphases, ana-
phases, and telophases (Table l) as well as binucleate pollen (Table 2).
With a normal course of mitosis in Tradescantia paludosa micro-
spores, the mitotic figures change as follows. In the early inter-
phase, the nucleus of the microspore is in the center of the cell; it
then shifts to one of the edges where it remains even in the period
of early prophase. During the second half of the prophase, the nucleus
moves to the center and remains close to the flat wall of the cell. In
the metaphase, the axis of the spindle is so situated that the chromo-
somal plate is always parallel to the flat wall. We recorded figures
reflecting both impairment in the regular movement of the nucleus and
impairment in the mechanism of passage of the mitosis itself. We divid-
ed these figures into 6 groups.
Group 1. The nucleus in the prophase did not go to the center of
the cell. It remained in a corner, but the nuclear cycle did not appear
to be impaired, because the chromosomes were in the form of metaphase
bodies and even split as in the anaphase and telophase.
Group 2. The chromosomes formed a "rosette". The nucleus in the
prophase moved to the center, but in the metaphase the chromosomes were
not found in the equatorial plate but were collected in bundles at the
flat wall of the cell very tightly squeezed by the centromeres.
Group 3. The direction of the axis of the spindle changed so that
the chromosomal plate in the metaphase was on another plane and, as a
result, the telophases and nuclei of the binucleate pollen were also
located on another plane. It will be noted that the position of the
nuclei in binucleate pollen may change even after they are correctly
situated, a phenomenon that should be borne in mind when analyzing these
cases. We identified this as a separate group 6.
Group U. Individual nonbroken chromosomes lagged.
Group 5. Three- and four-pole mitoses and, as a result, tri- and
quadrinucleate cells .
H
ro
OD
Table 1.
Number of impaired mitotic figures in Tradescantia paludosa microspores
exposed to space flight factors (analysis of anaphases and telophases)
Mitotic phases
exposed to
the factors
O CO
H
• H
O <U
a
No. of im-
pairments
Including
Name of
Group 1
Group 2
Group 3
Group h
spaceship
Abso-
lute
As per-
cent
Abso-
lute
As
per-
cent
Abso-
lute
As
per-
cent
Abso-
lute
As
per-
cent
Abso-
lute
As
per-
cent
Vostok k
Late inter-
phase, early,
712
15
2.H+O.5I4.
3
0.1+2
6
O.85
k
O.56
2
0.28
Fixed by Popovich
middle, and
56 hours after
late prophase,
the launching
metaphase
Vostok 3
Middle, late
interphase,
14-01
h
0.99+0.50
1
0.25
2
0.1+9
1
0.25
-
-
Fixed 18 hours
early prophase
after landing
Vostok It-
Middle inter-
phase
83
2
2.1t-0+1.68
-
-
-
-
1
1.20
1
1.20
Fixed 1+8 hours
after landing
Control
1000
1
-
-
~
-
-
-
-
—
I -
-
Table 2. Number of impaired mitotic figures in Tradescantia
paludosa microspores exposed to space flight factors (analy-
sis of binucleate pollen)
Mitotic phases
exposed to
the factors
w
H
• i-t
CD
a
Group 5
Group 6
1 >>
Name of
spaceship
Abso-
lute
As percent
Abso-
lute
As percent
Ct3 -P
H H
<D vH
Vostok h
Fixed by Popovich
56 hours after
the launching
Binucleate
pollen
500
1
0.2+0.197
11
2.2+0.65
2.39 1
Vostok 3
Fixed 18 hours
after landing
Late inter-
phase, early,
middle, late
prophase
500
k
O.8+O.39
13
2.6+0.71
2-99
Vostok h
Fixed I4-8 hours
after landing
Middle, late
interphase
500
2
O.Ih-0.28
7
l.U+0.53
1.66
Control at space
center
-
500
-
-
2
O.lH-0.28
-
Control in
Moscow
-
500
-
-
1
0.2+0.197
-
Compared with the control at the space center
H
ro
130
We used Trades cant i a microspores as a model in studying the effect
of space flight factors on the mechanism of mitosis. Naturally, the
method of preparing the specimens has to be perfected in order to elimi-
nate the possibility of artifacts. It will be noted that the figures in
groups 1, 2, k, and 5 cannot appear if the specimens are poorly pre-
pared. However, reorientation of the nuclei in groups 3 and 6 can take
place. Thus, one must be especially careful when analyzing these
groups of changes.
Ionizing radiation can, of course, impair mitosis, but the dose
must be fairly high. For example, a ii-OO r dose of X rays in our ex-
periments had no effect at all on the microspores. Nor did accelera-
tions of 5000 g impair mitosis. Presumably, the main reason for such
changes is weightlessness, but experiments will have to be designed
more rigorously to prove this.
One must also bear in mind that the effect of combined factors on
the cell is never a simple addition of the number of changes induced,
but rather new qualitative changes.
QUALITATIVE (STAGE) EVALUATION OF FLIGHT FATIGUE
Ye . A . Derevyanko
It is generally acknowledged that flight fatigue is essentially
nervous and mental in origin. Thus, in studying fatigue, considerable
attention is paid to the CNS, whose function is characterized by several
indices- -instability, relationship between excitation and inhibition,
etc.
In the presence of unfavorable factors, these indices, at first,
change unequally. Investigations made by the V. Ye. Vvedenskiy-A. A.
Ukhtomskiy school revealed that in the initial phase of exposure to a
parabiotic agent, excitability and rate of conduction of impulses de-
creases while the accommodation constant increases, instability grows,
and chronaxie and the refractory stage shorten. In the transitional
pha.it, on the other hand, excitability increases and the accommodation
constant decreases. It is only in the final phase that all the indices
testify to functional deterioration—the development of parabiosis.
Investigators likewise encounter a variety of changes in the in-
dices ("if CNS function when studying fatigue. As a rule, some methods
131
regularly show a decrease in fitness, others an increase, still others
show no clear-cut changes.
The conflicting results led some investigators to search for me-
thods that would enable them to evaluate the depth of fatigue from a
quantitative analysis of the changes, but all efforts proved futile.
The fact is that none of the available methods permits a quantitative
evaluation of fatigue, apparently because of the phase quality of the
changes in the indices .
In investigations conducted jointly with V. P. Zagryadskiy, P. N.
Oblapenko, P. Ya. Nurdygin, A. A. Kupriyanov, N. D. Zavalova, T. I.
Zhukova, I. P. Korenev, and others, we found that in the onset of fly-
ing fatigue, just as in the development of parabiosis, the indices of
CNS function change at first in different ways. On the basis of these
investigations, we selected a number of methods with varying sensi-
tivity to developing fatigue.
The highly sensitive methods include a determination of the criti-
cal rate of coalescence of light flashes and the duration of after-
images. Moderately sensitive methods include a determination of muscu-
lar endurance, time of a simple motor reaction to light and sound, time
and accuracy of differentiation of sounds of varying intensity. Methods
of low sensitivity include a determination of muscular strength and mo-
bility of the motor analyzer (tapping test).
It was impossible with the intensity of the flight load under study
to detect any clear-cut changes in the indices of the methods used to
measure certain mental processes (memory, attention, speed and accuracy
of reading instruments, etc.). On the other hand, V. A. Petrovykh and
B. L. Pokrovskiy noted a distinct lowering of the functional level of
these processes after a very heavy flight load.
It was found that most of the methods mentioned above, show an im-
provement in results at the beginning of a load and begin to decline
only later. The highly sensitive methods are the earliest to show an
improvement in results, but are also the first to reverse. Therefore,
at a time when these methods are showing a deterioration in results,
weakly sensitive methods show an improvement. As fatigue intensifies,
this group too begins to reverse so that the results of the investiga-
tions become increasingly alike (Table l).
Investigations showed that trace excitation has a tremendous effect
on efficiency. Right after the plane lands, most indices, owing to the
excitation prevailing in the CNS, point to a high level of efficiency.
As the excitation is extinguished, symptoms of fatigue become increas-
ingly evident (Table 2). Therefore, the degree of fatigue should be de-
termined after the excitation caused by emotional flight factors has been
extinguished in the CNS.
132
Table 1. Dynamics of change in indices in the development of fatigue
caused by flight activity of varying intensity
Intensity of
flight load
Nature of
Highly sensitive
method s
change, in percent
Moderately Weakly sensitive
sensitive methods
method s
Low-
+68/ -12(20)
+27/ -19(5*0
+17/-5(78)
Moderate
+ 7/ -36(57)
+22/-20(58)
+36/o(6U)
Above moderate
0/-80(20)
+ 7/-te(5l)
+20/-l3(67)
High
-
+ 6/-70(24)
0/-57(^3)
Note. In the numerator - the number of cases of improvement in re-
sults; in the denominator - deteriorations; in parentheses - virtually
unchanged .
Table 2. Nature of the change in simple conditioned motor reactions
in fliers during a day's flying under
a heavy load
Indices
Before
After the
After the
After the
15-30
Flying
first flight
second flight
third flight
minutes
after
conclusion
of the
flights
Reaction
time in o
185
177
150
172
219
As percen
of
t 100
96
86
93
118
investiga-
tions
before
flying
.
133
Our investigations provide additional confirmation of A. A.
Ukhtomskiy ' s view that a feeling of weariness is a delicate and relia-
ble index of incipient fatigue and that the early stages of fatigue do
not impair the "functional harmony of the organism" or decrease effi-
ciency. They also demonstrated that using methods which produce re-
sults largely dependent on volition introduces an undesirable vari-
ability.
The findings presented above made it possible to develop a stage
system of evaluating the depth of fatigue.
The following data are used:
(a) Subjective condition of the flier.
(b) Observations of the flier's behavior.
(c) Nature of the flights.
(d) Dynamics of nervous and mental tension.
(e) Results of investigations using methods of varying sensi-
tivity to developing fatigue.
The characteristics of the three stages of fatigue were described
in detail in F. P. Kosmolinskiy and Ye. A. Derebyanko's book Utom -
leniye letnogo sostava (Fatigue in Flight Personnel) (1962). The
proposed approach has several shortcomings that should be corrected:
(a) Little use is made of weakly sensitive methods, the number of
which should be increased.
(b) The results of several methods depend to some extent on the
level of volition.
(c) It is not quite clear just which aspects of the state of the
CNS are characterized by most of the methods selected for use in inves-
tigations. For example, there is still no consensus even on the parti-
cular aspect of the CNS that is characterized by a "simple" conditioned
motor reflex (B. M. Teplov) .
13^
PSYCHOPHYSIOLOGICAL CHARACTERISTICS OF INSTRUMENT PLYING
Ye. A. Derevyanko and N. D. Zavalova
Most of a pilot's efforts in instrument flying are directed at re-
taining and changing the current flight parameters in accordance with
his evaluation of the incoming information and the flight plan. Obtain-
ing information on flight conditions to guide his actions, the pilot
manipulates the controls to change the plane's position. Flying is a
continuous process of sensorimotor coordination in which the pilot,
besides visual signals, receives sound, acceleration, and proprioceptive
signals. It is the visual information, however, as has been demonstrated
by flight experiments, that has the greatest influence in retaining or
changing the mode of operation. Attempts to keep a plane flying hori-
zontally with no visual information available resulted in a significant
change in the spatial position and flight parameters during the first
minute of blind flying and the pilot lost his spatial orientation.
Visual information in instrument flying is different from that in
visual flying. First of all, information about the spatial position
of the plane has to be processed by the pilot. Secondly, information
reaching the pilot from instruments is discrete because there are in-
terruptions in the perception of the readings of each instrument. The
information comes in parts, i.e., it is given out by different instru-
ments or by different markings on the same instrument, and the pilot
has to synthesize the individual signals into a complete image.
The stream of data reaching the pilot can be arbitrarily divided
according to function into control and correcting information. The
former applies to the mode of operation, whereas the latter is needed
to perform an action designed to maintain or change the current flight
parameters. The instruments play different roles from the standpoint
of providing control and correcting information. The pilot controls
the flight conditions with all the instruments (altimeter, course
indicator, variometer, gyro horizon), and a change in the readings of
any of the instruments may signal the start of an action. However,
the pilot receives correcting information mainly from the variometer
and gyro horizon. These, then, are the instruments that a pilot uses
in blind flying. According to I. A. Kamyshev, a pilot looks at them
70 percent of the time.
The need of correcting information is dictated by the complexity
of motor activity in controlling a plane. This activity cannot be
considered a chain of simple motor reflexes ( signal movement). It
consists of two main elements: (a) perception and evaluation of the
readings of the instruments, (b) sensorimotor coordination of movements.
135
In controlling the mode of operation, the pilot receives and
processes incoming information. The processing culminates in a deci-
sion to act. As soon as the pilot decides, the purely sensory elements
of his activity ends. The performance of an action to retain or change
the mode of operation includes the execution of movements based on a
continuous flow of correcting information. The performance of motor
acts aimed at retaining or changing the current flight parameters takes
a good deal of time. The correcting information that arrives during the
performance of a motor act does not permit instantaneous measurement of
the amplitude and duration of deviation of the control stick. The need
of constant correction of movements is due to the fact that the nature
and duration of motor acts aimed at the same goal fluctuate considerably.
It seems that sensorimotor correction of actions is the central part
of the process of controlling an airplane and it requires active atten-
tion on the part of the pilot throughout the flight.
The process of receiving and evaluating instrument readings, apart
from the performance of movements for control purposes, is not complex.
Laboratory investigations have shown that a little training will enable
unskilled subjects to determine the spatial position of an airplane
from instrument readings just as quickly and as accurately as veteran
pilots, with 2-2 l/2 seconds spent on perceiving and evaluating the
readings of the principal instruments. In one flight experiment, after
opening the instrument panel, the pilot began to make the first movement
to bring the plane into a horizontal position within 0. 3-0.8 second, i.e..
he evaluated the situation very quickly.
Thus, analysis of a pilot's actions in controlling an airplane shows
that sensorimotor coordination of movements to control the craft is the
most complicated part of his work during an ordinary flight. The per-
ception of instrument readings, reconstruction and maintenance of his
impressions on the current mode of operation up to the time that he
takes action, is not difficult for an experienced pilot.
The coordination of movements with instrument readings is the
"bottleneck" that may cause loss of time and create tension if a compli-
cation should develop. Successful control of a plane does not require
rapid movements; it depends on accuracy of measurement and smoothness of
movements. The existing set of instruments provides little help for the
pilot in selecting the most effective movements. The information he
uses to correct his movements has to be considerably processed and
recoded . It reaches him in discrete form so that it is impossible for
him to perform an immediate and precise motor act without correcting
movements.
The pilot's task can be eased and extra time provided chiefly by
helping him in the performance of motor acts. This can be done by
changing the instrument readings. Instruments should yield coded
136
information in maximally convenient form and decide for the pilot the
amount, intensity, and smoothness of movements required for control
purposes. That is to say, they should issue clear commands as to how
an action should be performed at each particular moment.
SELECTION OF INDIVIDUALS FOR FLIGHT TRAINING
T. T. Dzhamgarov
The selection of individuals for flight training is an urgent
problem, whose theoretical and practical aspects have been inadequately
considered. The existing methods -- somewhat one-sided we believe --
provide no means of studying motor abilities, some of which are ex-
tremely important for successful flight training. They are also rather
passive in that they are designed simply to determine the degree of fit-
ness for flying, but fail to indicate ways in which the necessary qual-
ities can be developed.
The purpose of investigations that we conducted with our colleagues
(V. L. Marishchuk, N. V. Sysoyev, K. I. Brykov, and L. V. Yakusheva) was
to devise and verify experimentally under flight school conditions:
(a) methods of predicting the capacity for flight training and (b) phy-
sical conditioning techniques to correct individual shortcomings in ac-
quiring flying skills. Four series of experimental investigations were
run over a period of k years (1959-1963).
The basis of the selection method used in our investigations was
a combined study of certain motor abilities and individual psychologi-
cal traits that are most conducive to successful flight training. The
examination program for the candidates took cognizance of the data de-
rived from a preliminary analysis of the reasons for training failures.
Among the motor abilities studied were the speed of reflexes to
complex signals and delicate coordination of movements. These abili-
ties were also studied in conjunction with exercises involving the
diversion of attention and artificially stimulated emotional stress.
Special apparatus was used in the tests.
The main criteria used in evaluating the results were the objec-
tively recorded speed and accuracy with which the control exercises
were performed and the degree of change in these indices during the
examination (for characteristics of the process of acquiring motor
137
skills) and also when the conditions for performing the exercises
were changed (for characteristics of the ability to shift attention
rapidly and emotional stability.) . At the same time, the behavior and
actions of the subjects were systematically observed. In addition,
some autonomic changes in performing the exercises were recorded in
order to evaluate individual "stress reactions".
A special physical training program was usually conducted during
the period of theoretical instruction. Depending on the concrete
shortcomings revealed during the selection examination, this training
was aimed chiefly at: (a) coordination and precision of movements,
(b) speed of movements and actions, ability to divide and switch atten-
tion, (c) emotional stability and techniques of mastering tension.
The showing in the initial flight training was the principal basis
for evaluating the prognosis of flying capabilities and effectiveness
of the special physical training program. The following parameters
were used in the evaluation: number of flights before the first solo
take-off, the amount of flying time before the first solo take-off,
flight progress, opinion of instructors on the desirability of further
training, and data on dismissals for unsuitableness.
The effectiveness of our methods was confirmed by: (a) a clear-
cut relationship between the candidate's examination ratings and the
results of the initial flight training and (b) the high accuracy in fore-
casting the instances in which flight training was unproductive (75--
80 percent) or, conversely, when it was highly successful (95-100 per-
cent) .
The usefulness of the special physical training program to elim-
inate individual shortcomings was revealed by the fact that the
trainees in the experimental group were on the average 20-30 percent
more successful than the control in carrying out equivalent parts of
the program.
Some idea of the accuracy of the predictions and degree of ef-
fectiveness of the special physical training program 1 is provided by
the figures presented in the table above.
These data and the relative simplicity of the examination testify
to the practicality of the proposed method. It will easily identify
Tr. Note: Not included in the text.
138
the following groups: (l) candidates with pronounced shortcomings that
render their admission to flying school inadvisable, (2) individuals
with outstanding flying capabilities who should be specially recommended
for admission to flying school, (3) individuals with shortcomings that
can be corrected by special physical training during the period of
theoretical instruction.
The special physical training designed to supplement the regular
exercise program should be regarded as an essential part of the train-
ing of future fliers.
THE POSSIBILITY OF SUBSTITUTING HELIUM FOR NITROGEN
IN THE CABINS OF SPACECRAFT
A. G. Dianov and A. G. Kuznetsov
The possibility of substituting helium for nitrogen is of consider-
able interest in connection with research on the microclimate of space-
craft cabins . This substitution seems feasible both from the physio-
logical and from the technical standpoints : because helium is less
soluble than nitrogen in liquids and, especially, in fats, an atmosphere
consisting of oxygen and helium is not too conducive to the decompres-
sion disorders that may arise in human beings in the cabin of a space-
craft when the pressure drops. This assumption is supported by studies
on the use of helium to prevent caisson disease in divers (M. I. Yakobson,
1950) and theoretical investigations (Roth, 1959)-
The substitution of helium for nitrogen eliminates the possibility
of harmful actions to humans by radioactivity. These actions can arise
under the influence of cosmic radiation on nitrogen molecules (Bowman
and Dingman, i960). The high thermal conductivity of helium makes it
reasonable to assume that human beings in a spacecraft cabin with a
helium-oxygen atmosphere will be more tolerant of higher ambient tem-
peratures than in air. If this is confirmed experimentally, helium will
play a major role in protecting man from the high temperatures that may
develop in a spacecraft. The use of a helium-oxygen atmosphere in a
spacecraft will make it possible to reduce the vehicle's weight at
launching because helium has one- seventh the density of air. Moreover,
helium will be valuable if the spacecraft should lose its airtightness,
because helium is the best available leak tester. There is also reason
to believe that the substitution of helium for nitrogen will result in a
decrease in the amount of energy needed for enforced ventilation in the
cabin.
139
The effect of a helium-oxygen mixture on man and animals has
been studied by foreign and Soviet authors (Barach, Benke, Cook,
Orbeli, Zal'tsman, Boriskin, Gul'tyayev, Savin, and. others). Ex-
periments demonstrated that animals can remain for a long time (up
to 3 l/2 months) in a gas medium in which the atmospheric nitrogen
has been replaced with helium. In a temperature range of 18-22° C,
helium, which is a better heat conductor than nitrogen, increased gas
exchange in the animals by intensifying the loss of heat. When the
helium-oxygen mixture was heated to 27-29°, however, no significant
changes were noted in the animals.
The effect on man of substituting helium for nitrogen was investi-
gated in experiments of no more than a few hours' duration (use of
helium in deep-water descents of divers, in treatment of certain di-
seases of the respiratory organs, etc.) Results showed that for a
short time man can breathe a helium oxygen mixture not only at
normal but also at high pressure (up to 16 atmospheres). However, it
is important to note that in these experiments the helium-oxygen mix-
ture was used only as a breathing mixture, not as a gas medium in
which man was to remain for some time. To date there have been no
long-term experiments testing this possibility.
The purpose of this investigation was to study the possibility
of man's remaining for a long period of time in a pressurized cabin
in which helium replaced nitrogen. Two experiments lasting 22 and
30 days were carried out with two groups of subjects who remained in
a helium-oxygen mixture 10 and 25 days, respectively. The CNS, respira-
tion, cardiovascular system, gas exchange, heat exchange, speech, hear-
ing, as well as behavior and general well-being, were kept under obser-
vation.
Results showed that helium, due to its high thermal conductivity,
markedly affected heat exchange. Exposure to the helium-oxygen mix-
ture at temperatures comfortable for air (18-24°) resulted in apprecia-
ble cooling of the subjects, as reflected in a sensation of cold and a
lowering of skin temperature.
In the helium-oxygen medium, the zone of heat comfort for the
subjects when awake during the day ranged from 24.5 to 27. 5° and at
night while sleeping - from 26 to 29°. These changes were caused by
the more pronounced cooling properties of the helium-oxygen medium as
compared with air. The experimental data examined below 1 were obtained
mainly at the comfortable temperature of a gas medium in a pressurized
cabin.
Tr. Note: Not included in the text.
llj.0
Investigations of CNS functions made by V. F. Onishchenko, V. V.
Boriskin, P. A. Gul'tyayev, A. V. Sergiyenko, and others showed that
inhibition gradually developed in the subjects ' cerebral cortex in the
course of the experiments, as revealed by the appearance of low- frequency
oscillations on the EEG and by a slight lengthening of the latent period
of the conditioned motor reflexes. Analysis of data indicated these
changes were caused not by the substitution of helium for nitrogen, but
by the influence of prolonged hypodynamia and relative isolation. The
general sense of well-being, behavior, and efficiency of the subjects
did not change in the helium-oxygen medium.
The indices of the external respiration, cardiovascular system,
gas exchange, and energy expenditure of the subjects under the condi-
tions of basal metabolism or in a state of relative rest likewise did
not change significantly. However, the use of a functional test in the
form of measured physical exercise showed that minute ventilation, car-
diac rate, amount of oxygen utilized and energy expended gradually in-
creased the longer the experiments lasted. These changes too were not
attributable to the helium- oxygen medium, but to prolonged hypodynamia
and relative isolation. There was a distinct, progressive increase in
the deconditioning of the subjects as the experiments continued. Each
additional physical exercise required more and more exertion on the part
of the respiratory and cardiovascular systems and gas exchange.
The investigations of I. Ya. Borshchevskiy, V. S. Kuznetsov and Yu.
V. Krylov showed that breathing a helium-oxygen mixture markedly affects
speech, as reflected in a shift of the spectrum toward the high frequen-
cies by a value of the order of 0.7 octave. Clarity of speech tends to
deteriorate, although not as far as the level of permissible values of
intelligibility. The auditory function does not change appreciably.
The experiments described above have demonstrated that man can
remain a long time (up to 25 days) in a pressurized cabin in which helium
is substituted for atmospheric nitrogen.
EXCRETION OF 17-0XYC0RTIC0STER0IDS IN AN INVESTIGATION OF
THE EFFICIENCY OF AIRPLANE CREWS ON LONG NIGHT FLIGHTS
I. G. Dlusskaya, F. L. Kosmolinskiy and N. A. Fedorov
Investigators of flier fitness under the conditions of long, tense
flights used more than physiological, psychological, and clinical meth-
ods. They devoted considerable effort to determining changes in the
homeostasis of the internal fluids, including the hormones.
141
The question of human efficiency in critical situations has long
interested scientists. Body reactions designed to preserve the con-
stancy of the internal environment and to ensure normal functioning of
organs and systems have been described in the reports of Soviet physiol-
ogists, who assign the nervous system a leading role in the maintenance
of homeostasis.
Besides directly influencing the resistance of the organism, the
nervous system is also responsible for humoral regulation- -the activity
of the endocrine glands- -as reflected in the research of L. A. Orbeli
on the adaptation- trophic influence of the nervous system on the state
of the tissues and peripheral neuromuscular apparatus. Speaking of the
body's reserves in performing a given task, we might also mention H.
Selye"s theory of the adaptation syndrome, the heart of which is the
reaction of the pituitary-adrenal system, i.e., in response to various
external agents (pharmacological, physical, infectious, neuropsychic,
etc.), secretion of the hormones of the anterior lobe of the pituitary
(ACTH) increases as does that of the adrenocortical hormones. An im-
portant element in this view is the ability of the adrenocortical hor-
mones--the glucocorticoids--to hasten the conversion of proteins into
carbohydrates and thereby increase the energy reserves of the organism.
It is reasonable to suppose that such a mechanism of "emergency" utiliza-
tion of protein reserves evolved and became fixed phylogenetically when
it was vitally important for animals in danger or in the excitement of
hunting to be able to mobilize quickly all their resources, including
the utilization of proteins for energy purposes.
The adrenal cortex of man and mammals synthesized three kinds of
steroid hormones: (a) the glucocorticoids, of which the main one in
man is hydrocortisone, (b) the mineralocorticoids (aldosterone), and
(c) the male sex hormones (adrenosterone and testosterone). In re-
sponse to an increase of ACTH in the blood, the secretion of other
hormones, chiefly the glucocorticosteroids, also increases.
To evaluate the secretion of glucocorticosteroids by the adrenal
cortex, one may calculate the content of any of these compounds in the
blood or their excretion with urine. It is technically more difficult
to do so in the blood, for the material is poorly preserved and it is
not easy to take blood when required, especially during a flight. It
is easier to investigate hormones in urine, and the material is more
readily preserved. Moreover, the urine collected during a flight is a
unique reflection of the biochemical changes that have taken place.
Besides free hormones, the urine contains their metabolites and com-
pounds with glucuronic acid. The determination can be made from the
amount of corticoids entering the blood, which can be used as the
basis of judging the overall reaction of the pituitary-adrenal system.
Ik2
We determined the total bound and free 17-oxycorticosteroids after
long night flights involving refueling in the air. Similar investiga-
tions were carried out in 1958 by Marchbanks, who observed a significant
increase (twofold) in the amount of 17-oxycorticosteroids excreted with
urine during a 23-hour flight only in the captain, the person mainly re-
sponsible for the flight , for landing, and for refueling in the air.
The changes in the other members of the crew examined- -navigator, radio
operator, and second pilot- -were insignificant and well within normal
limits.
I. V. Fedorov and G. G. Sturua, who reported (1961) on an investi-
gation of fliers taking part in a succession of short ( 30-it-O minute)
flights, found that on nonf lying days the hourly excretion of steroids
during the day was 3O-5O percent higher than during the night . On fly-
ing days, however, the hourly excretion during the first flight was
double the original level and it even increased somewhat during the
second flight. Within a few hours after landing the values returned
to normal.
The present investigation focused specifically on fliers during
long night flights . Urine was collected immediately before the take-
off, immediately after landing, and during the first 6 hours after
landing (there was generally a 6-hour rest period). The urine was pre-
served and later analyzed for its content of 17-OH-KS by the Silber-
Porter method as modified by Yudayev. In processing the data, account
was taken of the excretion of 17-oxycorticosteroids in 7/hour during
three periods: an average of 1 hour before a flight, after 1 hour of
flight, and 1 hour after post-flight relaxation.
A noteworthy feature of the dynamics of the hormonal reactions was
that during the hours of flight there was a relatively low level of
excretion, but a fairly high level during the hours of post-flight re-
laxation. A significant increase in hormonal excretion during flight
occurred in 2 controllers (by 80 and 23O percent) and in 3 captains (by
100, 200, and 500 percent, i.e., 2- to 6-fold).
The flight with assignment not completed was particularly inter-
esting. The captain and controller showed a substantial increase in
hormonal excretion during the flight (by 200 percent), and it remained
high even during the post-flight hours of relaxation. Yet hormonal
excretion in the second pilot did not change during the flight hours,
although it increased during the first post-flight hours. A 5-fold
increase in excretion of steroid hormones during the flight was observed
in the captain, who carried out a complicated assignment. An increase
in excretion in the other members of the crew took place only in the
hours of relaxation.
143
The earliest hormonal changes (during the flight) took place in
the captains and controllers because they have the main responsibility
on this type of airplane. The duties and experiences of the second
pilots were simpler and the increase set in only during the post-flight
hours .
An interesting fact revealed during the examination of several mem-
bers of the same crew was that the hormonal reactions in the captains
and controllers or in the controllers and second pilots on the same
flight were similar and assumed the form of parallel curves on graphs.
This was apparently the result of similar flying conditions and emo-
tional stress in these members of the crew.
In summary, the excretion of steroid hormones with urine increased
significantly during long night flights mostly in the plane captain and
controller, who performed complex tasks. When such flights were rela-
tively uneventful, hormonal secretion in the crew changed very slightly
during the flights, usually decreasing. When the flight was over, dur-
ing the first 6 hours of relaxation, there was a marked increase in ex-
cretion (by 50-150 percent) over the pre -flight level in 12 of the l6
persons examined.
This phenomenon can be attributed to the length and tension of the
flights and to the fact that they took place at night (from about 2200
to 0600 hours), when the reactivity of the pituitary-adrenal system is
different (somewhat lower) from that during the day.
VESTIBULAR INFLUENCES ON THE SMOOTH MUSCLES OF THE SMALL INTESTINE
AND BLOOD VESSELS AFTER TRANSECTION OF THE SPINAL CORD AND
VAGUS,. CERVICAL SYMPATHETIC, AND SPLANCHNIC NERVES
A. S. Dmitriyev and Ye. V. Burko
G. Brown in 1 Q Q pioneered the study of vestibular autonomic reac-
tions with his investigations of respiration in frogs subjected to
progressive vertical accelerations. Later, as a result of the rapid
development of science and technology; high-speed travel on the earth
and, above all, in the air; and need to solve a number of clinical
problems, scientists became interested in the physiology of the vestibu-
lar apparatus. Many reports were published on the effect of vestibular
stimulation on different autonomic and animal functions. Extensive
experimental material now exists on the cortical and subcortical me-
chanisms of vestibular influences on the striated musculature (Ewald,
144
1892; Voyachek, 1908; Quicks, 1922; Magnus, 1924; Khilov, 1929, 1952;
Yarotskiy, 1937; Asratyan, 1940, 1947; Bakhvalova, 1950; Min'kovskiy,
1953; Beleceanu-Stolnich, Faluts, and Laurian, 1954; Dmitriyev, 1953>
1958; others).
However, the physiological mechanisms of the labyrinthine in-
fluences on the smooth musculature have not been adequately studied.
While a relatively large number of studies have been published on
changes in blood pressure caused mainly by decreased tone of the vascu-
lar wall after stimulation of the labyrinth (Spiegel and Demitriades,
1922; Perekalin, 1928; Khilov, 1933, 1958; Lozanov, 1938; Klosovskiy
and Semenov, 1947; Khechinashvili, 1958), there are only isolated
reports describing vestibular influences on the smooth muscles of the
gastrintestinal tract (Spiegel and Demitriades, 1922; Perekalin, 1928;
Suvorov, 1958; Rassvetayev, 1958; Khazen, 1958; Lopatin, i960) .
The purpose of this investigation was to study the characteris-
tics and mechanisms of the vestibular influences on the smooth muscles
of the intestine and blood vessels under the conditions of rotation in
a centrifuge at different speeds and with different radii and to deter-
mine the post-rotation changes in these indices after transection of
various autonomic nerves and the spinal cord. Study of these matters
will throw more light on the physiological mechanism of seasickness,
which is caused by stimulation of the vestibular receptors, and in-
cludes such reactions as nausea, vomiting, urination, defecation, change
in blood pressure, etc., — reactions under control of the smooth mus-
cles.
In acute experiments on dogs anesthetized with morphine -ether,
electromechanograms on a MPO-2 oscillograph recorded motility of the
ileum, tone of the intestinal wall, blood pressure, and respiration.
These indices were recorded continuously before, during, and after
even rotation of the animal, whose head was in the middle or on the
periphery of the centrifuge. Vestibular tests were made after trans-
ection of various nerve trunks and the spinal cord and after destruction
of both labyrinths. The transections were carried out in different
sequences.
The first series was devoted to a study of vestibular influences
on ileal motility and blood pressure, taking into account the radius
(from to 130 cm), speed (from 10 to 40 rpm) , and direction (clockwise
and counter-clockwise) of rotation. The second series focused on the
effect of vestibular stimulation on the same indices as in the first
series, but after successive transection of the vagus, cervical sym-
pathetic, and splanchnic nerves, and of the spinal cord at the level
of the 2nd -3rd thoracic vertebrae before and after exclusion of the
labyrinths of the internal ear.
145
The first series of experiments showed that ileal motility was
inhibited by rotation in all kk dogs. The latent period of this
reaction ranged from 5 "to 75 seconds, while the aftereffect appeared
3 minutes after the centrifuge was halted. Complete inhibition of
motility by rotation was noted in 177 tests, intensification of motor
activity in 35> temporary intensification and then inhibition in 2h,
and no changes in motility in 20 vestibular tests.
The animals were divided into three groups according to the prin-
cipal changes that took place in intestinal motility: (a) animals
with inhibition predominating (30); (b) animals with intensification
predominating (9); and (c) animals with an indistinct response to
stimulation of the labyrinth (5)-
It is interesting to note that the reaction of the ileum to ac-
celeration disappeared in almost all cases after bilateral destruction
of the labyrinths .
The changes in intestinal motility varied with the intensity of
the vestibular load. The greater the speed of rotation, the larger
the number of tests that revealed intestinal inhibition, with a pro-
portionate decrease in the number of tests that showed no definite
changes in motility. For example, after rotation at the rate of 10
rpm, no changes in motility were found in 11. 7 percent of the tests,
but after rotation at 30-40 rpm the figure dropped to 4.5 percent.
Arterial blood pressure (in the common carotid artery) under the in-
fluence of the accelerations fell to 20 mm Hg. More significant
changes in blood pressure were noted after caudocranial rotation, i.e.,
when the dog's head was on the periphery of the centrifuge.
The data obtained in the first series of experiments partly agree
with the data obtained in chronic experiments on dogs rotated at a high
speed (from 3 to 10 g) (Suvorov, 1958; Khazen, 1958) and after exper-
imental rolling (Rassvetayev, 1958) in connection with a study of the
effect of accelerations on gastric motility. However, these authors
did not set out to determine the relation of the vestibular apparatus
to these reactions because they used accelerations without excluding
the active participation of various extra labyrinthine systems in these
reactions. Nevertheless, they did show that gastric motility is in-
hibited by accelerations. Perekalin (1928) observed an intensifica-
tion of ileal motility in response to inadequate stimulation of the
labyrinth, but the data obtained in the present investigation concern-
ing the inhibiting effect of the labyrinth on ileal motility contradict
his findings.
ik6
The decrease in vascular tone (drop in blood pressure) that we
observed under the conditions of rotating in a centrifuge with a long
radius (130 cm) was apparently related to the function of the otolithic
part of the labyrinth.
The second series of experiments showed that the inhibition of
intestinal motility by accelerations persisted after bilateral transec-
tion of the vagus and cervical sympathetic nerves , but disappeared after
bilateral destruction of the labyrinths.
These findings do not agree with the data of V. Ye. Perekalin
(1928), who states that transection of the vagus nerves relieves the
motility intensified by calorization of the labyrinth with cold (15 )
or hot (^5°) water and decreases the tone of the ileal wall.
Transection of the spinal cord, vagus, cervical sympathetic, and
splanchnic nerves somewhat altered the nature of ileal motility, but
did not suppress the peculiar effect of accelerations. After both
labyrinths were excluded, the aforementioned rotation changes in intes-
tinal motility disappeared in almost all the experiments. It is evi-
dent that the smooth-muscle reaction to slight accelerations is vesti-
bular in origin and that it is executed by nerve mechanisms located in
the brain stem. However, it is still impossible to identify the spec-
ific pathways through which vestibular influences reach the smooth
muscles of the intestine. It is reasonable to assume that the efferent
part of the arc of this reflex includes more than just the fibers pass-
ing through the vagus, cervical sympathetic, and splanchnic nerves.
These reflexes can also be executed without the participation of the
spinal cord. This agrees with the well-known fact (Meshcheryakov, 1959)
that after transection of the spinal cord at the level of the 6th -7th
cervical vertebrae and extirpation below the transection site, there
are no significatnt changes in the motility of the alimentary canal.
However, our data do not preclude the possibility that the aforemen-
tioned nerve conductors participate in the labyrinthine influences on
the smooth muscles.
We have concluded from our preliminary findings that vestibular
reactions can be executed by nervous as well as by humoral mechanisms.
ikj
SOME DATA ON AN INVESTIGATION OF CHAIN CONDITIONED MOTOR
REFLEXES IN ANIMALS AFTER LONG EXPOSURE TO AN
ALTERED GAS MEDIUM
G. P. Doronin
Although electro physiology is now widely used in objective inves-
tigations of the CNS, the method of conditioned motor reflexes has not
lost its independent value in studying the effect of an altered environ-
ment on the formation of complex responses. The published data indicate
that the indices of conditioned activity are several times more sensi-
tive than those of other methods for determining the threshold values of
toxic products and many other injurious factors (Yu. P. Frolov, 19^4-4;
L. I. Kotlyarevskiy and A. G. Bukhtiarov, I960; others).
The use of chain motor reflexes in investigating the prolonged ac-
tion on animals of altered gas composition in inhaled air, rarefied
atmosphere , and some other factors that may occur in actual space flight
is of considerable theoretical and practical interest.
We performed experiments on white rats, using the method of chain
conditioned motor reflexes developed in the Department of Higher
Nervous Activity, Moscow State University (director, Prof. L. G. Voro-
nin) . This method was technically perfected by us jointly with engi-
neer B. A. Miloslavov. Using a relay system with temporary delay
circuits, which made it possible to switch on conditioned stimuli in
a definite sequence, we prepared an automatic electric device for pro-
longed (up to 2 months) investigations of chain motor reflexes in the
white rats.
It is known that, in chain motor reflexes, a highly specific motor
reaction corresponds to each stimulus in the chain. The correct execu-
tion of the preceding link is reinforced by activating the next stimulus
in the chain and the entire chain of motor reactions becomes an uncon-
ditioned stimulus. Numerous investigations (K- I. Kunstman, 1923; L. G.
Voronin, ±9^8, 1952; V. K. Krasuskiy, 195^; N. A. Rokotova, 195^; G. I.
Shirkova, 1955; others) have shown that the connection with the uncon-
ditioned stimulus of just the last or closing component of a chain deter-
mines the force of the individual links in a complex chain stimulus.
The first stimulus in the chain becomes the determining or "trigger"
component. Later, the sequence of the conditioned stimuli joined into
a chain becomes the main signal. The subsequent movement of the animal
is largely determined by the nature of the preceding proprioceptive
impulses.
11*8
The formation of temporary connections between the cortical cen-
ters excited by a chain of stimuli, the food center, and correspond-
ing projections of the motor analyzer results in the creation of a
"functional combination center" in the cerebral cortex. The use of
chain conditioned motor reflexes makes it possible to investigate the
delicate process of analysis and synthesis of the complex stimuli that
act in a definite sequence on a living organism.
It has been established that the structure of a chain motor reflex
is more or less vulnerable to the influence of unfavorable environmental
factors. In this regard, we investigated chain reflexes in the experi-
ments of A. G. Kuznetsov, S. G. Zharov, and N. A. Agadzhanyan, who
studied the effect of prolonged exposure to minimum levels of barometric
pressure and high concentrations of carbon dioxide in inhaled air
(pCOg ik. 2-35-6 Hg) . A sequence of movements corresponding to the
stimuli was formed and stabilized in white rats:
light — » movement to platform 1 -- light 2 -^movement to platform
2 -- sound of an electromagnet --> movement to the feed box.
The stimuli were switched and the food reinforcement was delivered
automatically as the animal passed across the contact platforms.
Conditioned inhibition was established by the first stimulus in the
chain and an additional component, blinking light. Meanwhile a dis-
engaging reaction was formed in the animals - movement to platform 3>
reinforced after a little while by activation of the chain of positive
stimuli. Execution by the animals of movements of the positive chain
against the background of the blinking light was interpreted as a
"disruption" of inhibition.
The system of conditioned motor reflexes formed simulated the
complex activity of animals in getting food and made the artificially
created situation resemble the conditions of a natural experiment.
Chain motor reflexes were studied in 10 experiments lasting from
2 to 60 days. The pattern of the changes therein was traced under the
conditions of normal and high C0„ content in inhaled air at altitudes
of up to 10,000 m.
With the pCOj about lh mm Hg (2 percent), there were fluctuations
during the first 2-3 days in the time of execution of the individual
links in the chain, usually the first or "trigger" link. The structure
of the chain reflex remained virtually unafffected. More characteristic
was a lengthening of the time of the motor reaction, which disrupted the
conditioned inhibition, as well as a complete loss of this movement and
appearance of searching activity, prolonged cleansing reactions, etc.
lk-9
With a pCOp of 35.6 mm Hg (5 percent) there was more pronounced
impairment of the established system of conditioned reflexes. As a
rule, during the first days of exposure the time of reaction to the
first stimulus in the chain increased by O.3-O.5 seconds, and losses of
individual links or execution by the animals of a variety of movements
unrelated to the signal value of the stimuli were common. There were
frequent "disruptions" of inhibition with execution of movements of the
positive chain against the background of the blinking light and omission
of the reaction releasing the conditioned inhibition. The chain motor
reflexes were restored during the second week of exposure to these
conditions, although at a somewhat different level. However, the reac-
tions to the conditioned inhibitory stimulus were irregular, testifying
to the increasing deficiency of internal inhibition.
The introduction of an additional factor - rarefaction - into the
experiments resulted in some peculiar conditioned activity by the ani-
mals the first day after they were "elevated". This was evidently due
to meteorism and to the transient influence of sound stimuli at the
time that the barometric pressure was lowered and the particular gas
medium created.
Maintenance of normal pC> 2 un der the conditions of a rarefied atmos-
phere ensured preservation of chain conditioned motor reflexes at more
or less the original level.
. Experiments with brief hypoxia showed that at an altitude of
4000-5000 m the structure of the chain motor reflexes became impaired
and phase states appeared. At 6OOO-65OO m some of the animals developed
complete inhibition of the previously formed complex systems of condi-
tioned motor reflexes.
Thus, it has been shown that the method of chain motor reflexes
is highly sensitive and useful in studying the effect of some factors
specific to aviation and space medicine.
150
CHANGES IN THE CAPACITY OF THE CENTRAL NERVOUS SYSTEM WHILE
LEARNING TO PILOT A TRAINING PLANE
V. A. Yegorov
An important aspect of aviation physiology and psychology is the
amount of information a flier perceives and processes. Studies have
shown a direct relationship between the amount of information perceived
and reaction time (Hick, Hayrnan) . Once the average time per signal is
determined, it is possible to calculate the reaction time for a great
many signals. In investigating the speed of perception and processing
of information, it is necessary to bear in mind that these change in
the course of training in relation to changes in the capacity of the
trainees while they are acquiring the ability to control the apparatus.
We investigated the problem in connection with a TL-1 trainer,
starting with the assumption that the trainee's capacity is a function
of the complexity of the task to be performed and the degree of skill
acquired. Experiments were performed on k8 healthy persons from id
to 28 years of age, none of whom had had any previous "flight" exper-
ience on the trainer or any flight training. Each subject was required
to react to a radio command by moving a certain control lever on the
trainer: in the first series - any one lever (a simple movement); in
the second series - two levers (a complex movement); in the third
series - the subject performed the same movements as in the second
series, but while "flying" he had to react to a command quickly and
correctly and to do his best to prevent other "flight" parameters
(except the one to be changed) from changing.
The movements were selected in accordance with the rules for
piloting a trainer and airplane, and the commands were grouped together
in such a way that in each succeeding group the information contained
in a signal was increased by 1 bit over the preceding group. The use
of mechanical and electrical systems made it possible to record (in
the form of curves on the tape of a K-12-21 oscillograph) all the
movements of the TL 1 control levers, readings of the main piloting
and navigation instruments, speech stimulus, pulse and respiration of
the subject.
The "landing approach exercise based on the straight line system"
was used as the training "flights". The amount of processed informa-
tion was calculated from Shannon's formula, which treats erroneous ans-
wers on conversion to capacity as a loss of information.
We studied changes in capacity in the course of acquiring skills
from all three series before the "flights" and after 5, 10, 15, and 20
151
training "flights". There was a total of 538 experiments, 275 of
which were training "flights" and 263 control experiments, with 27,792
measurements of reactions to commands.
We found that capacity is not a constant, that it changes as skill
is acquired. For example, the time required to process 1 bit of informa-
tion in response to various commands decreased by 16-46 percent with
simple movements by the 20th "flight", by 60-J0 percent with complex
movements, and by 47-71 percent with handling the controls "in flight".
As skill increased, there was not only a decrease in the times re-
quired to process 1 bit of information, but a linear relationship
appeared between the amount of information and processing time. This
did not occur in the experiments performed before the start of "flights".
Analysis revealed a relationship between the time required for pro-
cessing information and the complexity of the movements. For example,
the time required by trained individuals to process 1 bit of information
with simple movements was O.O96-O.II7" (capacity was 8.5-10.4 bits/sec,
respectively), but with complex movements the time was O.I8O-O.I89"
(5.2-5.5 bits/sec).
The time required to process 1 bit of information with complex move-
ments was always more than with simple movements. This difference grad-
ually leveled out during training in parallel with the development of
skills. For example, the time required to process 1 bit of information
before training averaged O.I69" with simple movements and 0.519 with
complex movements (an excess of 307 percent), but after 20 training per-
iods - 0.104" and 0.184", respectively (an excess of only 177 percent).
Execution of commands during a "flight" was a more complex motor
task, and it also influenced the time required to process information
(0.212-0.292" for 1 bit; 3.4-4.5 bits/sec), an increase of 0.057" for
each bit as compared with the "non-flight" movements.
A significant correlation (0.94 on the average) was noted between
the quality of execution of the flights and the capacity displayed in
taking the above-described tests. Capacity in the absence of trainer
control skills ("poor" execution of control flights) amounted to
4.9-6.9 bits/sec with simple movements, 2.3-4.1 bits/sec with complex
movements, and 0.7-2.2 bits/sec with movements involved in executing
"flights").
Capacity with formed skills ("excellent" execution of control
flights) with simple movements amounted to 8.3-11.2 bits/sec, 5.3-
6.6 bits/sec with complex movements, and 3.3-4.7 bits/sec with
movements "in flight".
152
To prevent the acquisition of skill in the course of repeated
control experiments from influencing the results of the investigation,
we checked the capacity of two subjects only after the acquisition
of skill in controlling the trainer (no control experiments were
performed during the training "flights"). The results, as in the
main group of subjects after the acquisition of skills, were such as
to suggest that the control experiments had no appreciable effect.
Thus, capacity or the inverse value (the time spent on processing
1 bit of information) is a good index of the complexity of the motor
component in a task to be performed and the degree of skill acquired
in controlling a flight trainer.
CHANGE IN BACK PRESSURE ON THE BODY AND TOLERANCE OF
RESPIRATION AT EXCESS PRESSURE
A. V. Yeremin and V. N. Alifanov
The main prerequisite of the proper functioning of an oxygen
supply system intended for respiration at excess pressure is that it
provide back pressure on all parts of the body equal to intrapulmonary
pressure. This depends to a large extent on the correct fitting of the
altitude -compensating suit (ACS). Since fitting is generally done "by
eye", there is, of course, no guarantee of uniform and adequate back
pressure when there is excess pressure in the lungs.
To determine how improper fitting of a ACS affects the tolerance
of respiration under pressure, we studied a number of healthy males,
20 to 30 years of age, observing functional changes during the breath-
ing of oxygen at excess pressure on the ground and at an altitude of
20 km (in a pressure chamber) with changes in external back pressure
(a) on the entire body, and (b) on individual parts of the body, thus
stimulating the defects of the ACS.
In our first series of investigations, we used a special oxygen
apparatus designed by V. S. Yakovlenko that enabled us to regulate
pressure separately in the hermetic helmet and in the compartments of
the ACS. In the second series, we used a suit with separate compart-
ments for the abdomen, chest, thighs, shoulders, forearms, and shins.
Pressure in the compartment of the tightening device of the ACS
was regulated in such a way that the pressure created on the body (or
individual parts) by the suit was JO, 50, and 30 mm Hg lower or 30 or
153
50 mm Hg higher than the intrapulmonary pressure, which remained con-
stant .
The sequence of the first series of experiments was as follows.
An excess pressure of 55 > 104, 126, or 136 mm Hg was created in the
helmet and the same pressure in the tightening device of the ACS.
Pressure in the compartments was then successively increased or de-
creased, as mentioned above. The same order was followed in the high-
altitude experiments, but pressure in the helmet was always 104 mm Hg.
There were two variations in the second series of experiments.
At first an excess pressure of 55 ram Hg was created in the helmet and
a corresponding back pressure in turn on the abdomen, chest, thighs,
shoulders, forearms, and shins (simultaneously). Then with a pressure
of 104- mm Hg in the helmet and a corresponding back pressure on the
body, the pressure was reduced (usually to zero) also in turn in the
individual sections of the compartments of the tightening device. High-
altitude experiments were performed with a pressure of 10K mm Hg. The
exposure of each set of pressures usually lasted no more than 5 minutes.
There was a total of 69 experiments: 49 in the first series, 20 in
the second. During the investigations we recorded the biolectric
activity of the heart (EKG), brain (EEG), some respiratory muscles (EMG) ,
saturation of blood with oxygen (oxymetry), blood pressure, and respira-
tion rate. The thoracic and abdominal cavities were X-rayed and pres-
sure in the helmet and ACS pressure on the body (at 9 points) were
measured. Also, account was taken of the subjects 1 impressions of their
own condition and findings of medical observation.
The results of the first series showed that external back pressure
consistently influenced the nature of the physiological changes only
as long as pressure in the helmet did not exceed 104 mm Hg. A decrease
in back pressure caused a proportional deceleration of respiration,
increase in the amplitude and duration of the EMG, and an acceleration
of the pulse. An increase in back pressure caused the opposite changes,
except in the pulse rate, which increased under these conditions too.
With pressures in excess of Wk mm Hg (126-I36 mm) in the helmet, regard-
less of the external back pressure, there was an acceleration of the
pulse and respiration as well as a continuous and intensified flow of
impulses from the respiratory muscles, which signified that the ACS had
inadequate compensating characteristics.
At an altitude of 20 km, a change in external back pressure was
subjectively tolerated better than on the ground. The amplitude and
duration of the EMG were less pronounced. The pulse, on the other
hand, became more rapid. The X rays showed that at high altitudes the
diaphragm was displaced upwards by the expanding gases of the intestine,
assumed a more normal position than in the ground experiments, and more
Ijk
actively participated in respiration. This was undoubtedly the reason
for the sensation of easier breathing at excess pressure at high alti-
tudes.
The saturation of blood with oxygen at high altitudes under all
pressure conditions came to 80-90 percent, but the bioelectric activity
of the brain scarcely changed. Total exclusion of the pneumatic system
of the suit at an altitude of 15 km did not reduce efficiency for 3-5
minutes.
Changes in back pressure on individual parts of the body under
both ground and high-altitude conditions produced similar reactions.
Changes in the EMG were greatest when pressure on the abdominal area
was reduced; breathing under these conditions was subjectively the most
labored. A decrease in pressure on the chest had the least effect.
Marked difficulty in breathing and very pronounced EKG changes followed
a reduction of pressure on the shoulders and, especially, on the thighs.
This was apparently due to the fact that the work of the compartments
in these areas also affected the adjacent areas (below the abdomen and
upper part of the chest) and that venous stasis developed (jar effect),
which was subsequently confirmed by I. H. Chernyakov, V. N. Polyakov,
and A. V. Yeremin. Exclusion of the compartments in the region of the
shin and forearms for up to 5 minutes had no significant effect on the
physiological functions or feelings of the subjects. The saturation of
blood with oxygen and bioelectric activity of the brain changed very
little, as in the first series of experiments.
Findings
1. In breathing at excess pressure under ground conditions and
at an altitude of 20 km, a discrepancy of ±50 mm Hg for 5 minutes be-
tween pressure of the ACS suit on the body and intrapulmonary pressure
had no major effect on basic physiological functions. A discrepancy
of more than 50 mm Hg resulted in labored breathing and marked cardio-
vascular changes, thus significantly impairing the tolerance of respira-
tion at excess pressure.
2. Good compensation of the abdomen and upper part of the thighs
was of the greatest importance. Compensation of the chest, shoulders,
shins, and forearms played a somewhat lesser role.
3. At an altitude of 20 km, even a relatively slight decrease in
back pressure on the body was satisfactorily tolerated for no more than
5 minutes, after which the "jar effect" developed, especially in the
region of the extremities.
hiiihmmih iiiiiwh^ mil mill
I*?
155
EFFECT ON MAN OF PROLONGED EXPOSURE TO ATMOSPHERE
WITH A HIGH CO CONTENT
2
S. G. Zharov, Ye. A. II 'in, Ye. A. Kovalenko, I. R. Kalinichenko,
L. I. Karpova, N. S. Mikerova, M. M. Osipova and Ye. Ye. Simonov
Most investigators believe that the air in spacecraft and stations
should be completely free of the accumulated COo products of metabolic
processes. There are some who disagree and recommend that excess COp
be used to regenerate oxygen photosynthetically, to prevent the
hypocapnia that arises in certain flight situations, and even to offset
the injurious effect of cosmic radiation.
These considerations led us to investigate the effect of high CO
concentrations on man subjected to a variety of space factors (accelera-
tions, weightlessness, radiation, hypoxia, hypodynamia, isolation,
rarefied atmosphere, etc.).
The literature provides few references on this subject. The per-
missible concentrations of CO established for the air of living quarters,
submarines, gasproof shelters, and airplanes cannot be applied to the
atmosphere of spacecraft and stations, because living conditions in the
latter differ considerably from those that obtain in vehicles operating
in a normal gravitational field.
According to Sheffer (1961), the C0 2 concentration of air inhaled during
a prolonged stay (about k2 days) in submarines should not exceed 0.5-
0.8 percent; an increase to 1.5 percent may cause pathological changes.
Our experiments dealt with the effect on man of prolonged exposure
(about 30 days) to atmosphere in a confined space with an average C0 p
content of 1 or 2 percent. They were performed in a 7 m3 pressure chamber
at an air temperature of 20 + 2° C, relative humidity of 1+0 -60 percent,
and C0 2 content in inhaled air of 19-22 percent. The concentration was
automatically regulated by a specially devised system accurate to 0.05-
0.1 percent COp (G. I. Badikov, B. A. Miloslavov, and G. K. Solov'yev,
1963) . The effect of the different COp concentrations was evaluated
from the following indexes: total CO content of the blood by Fisher's
method; alkaline reserve of the blood by Van Slyke's method; pH and pC0 2
156
of the blood (on a combination analyzer manufactured by the Gotard Com-
pany); partial pressure of COg and Op in alveolar air; pH, ammonia,
carbonates, and titration acidity of urine; EKG's; and arterial pressure.
Subjects were given physical examinations before and after exposure.
Efficiency and functional stability were evaluated from 6-lead investi-
gations of brain biocurrents conditioned motor reflexes, outlining of
geometric figures, and problem solving. The curve of cerebrocortical
reactivity was studied by M. N. Livanov's method.
There were two experiments with 2 subjects in each. Both were ex-
posed for 30 days : one to atmosphere containing 1 percent COp, the other
to 2 percent CO .
Results of the first experiment show that 30 days ' exposure to air
containing 1 percent CO had no significant effect on either the sense
of well-being, efficiency, or basic physiological functions. Pulse rate,
arterial pressure, EKG, tests with respiratory standstill, temperature,
and body weight remained essentially unaltered. Increase in pulse ex-
citability and in time required to outline the figures (G. D. Doronin),
and intensification of ex activity on the EEG (gradual increase in ampli-
tude of the cc waves and a index, exaltation of a waves with maximum in-
tensity of light as a stimulus) were approximately the same as in the
control experiments of equal duration (A. G. Kuznetsov, 1962).
Observed changes indicated a slight lowering of cerebral cortex and
cardiovascular function under the influence of hypodynamia and similar
stimuli. Total CO content of the blood (tCO ? ) in subject A. rose from
h.0 to 50 percent by volume and in subject N. from k6 to 53 percent by
volume, while the blood pH remained virtually unchanged. Due to the in-
creased CO tension in the blood, urinary ammonia and carbonates in-
creased and pulmonary ventilation rose during the first half of the ex-
periment by an average of 0.5-1 liter/m. During the second half, despite
the pCO increase in alveolar air and blood, pulmonary ventilation, by
virtue of adaptation to the CO effect, decreased by approximately the
same amount.
Thus, results of the first experiment show that prolonged exposure
(30 days) to atmosphere with a CO content averaging 1 percent increased
the pCO in alveolar air and caused both free and chemically bound COo
157
to accumulate in the blood. In view of this, we may conclude that under
such conditions human beings develop compensated gaseous acidosis . This
state can be regarded as completely reversible, owing to the insignificant
rise in pCO p and the relatively slight increase in tCO in blood, which
disappeared as soon as the experiment was over.
Subjects in the second experiment were found to have a larger accu-
mulation of both free and chemically bound COp in the blood, thus making
the changes in physiological functions more pronounced. For example, in
P., pCOp in alveolar air and in blood rose from 38-39 mm Hg to k^-k6 mm
Hg. Essentially the same changes were observed in the other subject.
P. 's alkaline reserve rose from 53 to 63-66 percent by volume, whereas
in the other subject it scarcely changed. This phenomenon probably
occurred because P., unlike U., engaged in 30 minutes of physical exer-
cise (an average load of 35OO-I+OOO kgm) twice a day, causing more rapid
accumulation of CO in the body.
In both subjects, during the first 15-20 days, there was a drop in
blood pH from 7. h.1-7. U.7 to 7.3U-7.38 units, respectively, indicating
noncompensated gaseous acidosis. Pulmonary ventilation throughout this
experiment remained above the original level by an average of 1.6- 3. 7
liters/min. U. 's blood pressure scarcely changed, while P. 's maximum
and minimum pressure was above the original level. P. complained of
heaviness in the head and general sluggishness during physical exercise.
In the aftereffect period, this subject had a persistent elevation of
minimum blood pressure to 95-100 mm Hg and decrease in the pulse differ-
ence to 20 mm Hg, indicating functional cardiovascular weakening. This
is also attested by a reduction in the time of breath holding on inha-
lation and exhalation and by an increase in pulse excitability during
exercise. Urinary excretion of ammonia and carbonates exceeded that in
the first experiment.
Whereas in the first experiment the EEG of both subjects showed an
intensification of a activity, which we ascribed to the more synchronous
activity of the brain cells under the influence of similar situational
stimuli, in the second experiment the a index and amplitude of the a, waves
decreased while the activity of the high-frequency oscillations became
intensified and that of the slow waves with a frequency of 5-7 cps de-
creased. The EEG changes resembled a desynchronization reaction. We
concluded that EEG changes in the second experiment were caused mainly by
increased CO tension in the blood.
Our study of the physiological indexes shows that, after a prolonged
stay (about 30 days) in the atmosphere of a confined place with a high
C0 2 content, man develops signs of acidosis, hypodynamia, and fatigue.
158
Acidosis intensified as the C0 ? concentration rises from 1 to 2 percent
and the time spent in the chamber increases. Efficiency remains fairly
high when the CO content averages 1 percent, but an atmosphere with 2
percent CCU causes a marked deterioration in ability to perform physical
exercises and gives rise to much more functional tension. However, the
ensuing changes are wholly reversible.
EVALUATING THE BIOLOGICAL EFFECTIVENESS OF SPACE FLIGHT FACTORS
BY MEANS OF THE LYSOGENIC BACTERIA E. COLI K-12 ( X)
N. N. Zhukov-Verezhnikov, I. N. Mayskiy, V. I. Yazdovskiy,
A. P. Pekbov, N. I. Rybakov, G. P. Tribulev, P. P. Saksonov,
N. N. Dobrov, V. V. Antipov, V. A. Kozlov, V. G. Vysotskiy,
B. A. Mishchenko, K. D. Rybakova, G. P. Parfenov,
V. V. Pantyukhova, Ye. V. Yudin and Ye. D. Aniskin
Biological experiments with objects varying in radiation sensitivity
are of considerable value in judging the genetic effects of space flight
factors. The most interesting of these objects are lysogenic bacteria,
which react to comparatively small doses of ionizing radiation with in-
duced phage production. Our experiments showed that roentgen and gamma
rays (0.2-0.U r), protons of various energies, and rapid neutrons cause
genetic damage to lysogenic bacteria. The inducing effect is directly
related to the irradiation dose and the "dose-effect" curves are ex-
ponential in nature. These findings enabled us to use the lysogenic
system in all the experiments on Soviet spacecraft.
This report presents the results of a study of phage production
by E. coli K-12 ( A.) in specimens exposed during the Vostok 3 and Vostok
h flights and in laboratory investigations on the combined effect of
vibration and irradiation.
Method
In the spacecraft experiments, we used suspensions of a 5-hour cul-
ture of E. coli K-12 (A,) of a certain concentration prepared in physio-
logical solution with 20 percent meat-peptone broth (total volume 1.5-
2 ml) added. The controls were suspensions in ampuls kept at the space-
port (essential control) and under laboratory conditions (technical
159
control). All objects were stored on ice. After the flights were com-
pleted, we determined the number of viable cells and phage -producing
bacteria (induced) in the experimental and control samples of the cul-
tures .
Since some free phage particles (spontaneous bacteriolysis) are
always present in cultures of lysogenic bacteria, we used an indirect
method of determining induced phage production, employing specific anti-
phage serum to inactivate the phage particles originating spontaneously.
Accordingly, specimens were taken from each sample and inoculated onto
meat -peptone broth.
The test tubes were placed in a water bath at 37 for 55 minutes
(latent period). Antiphage serum was added to the bacterial suspension
after conclusion of the latent period to suppress the spontaneous phage
particles. After 10 minutes the action of the antiphage serum was halted
by diluting the suspensions and adding streptomycin. Inoculations were
made by the method of agar layers in the presence of streptomycin bacteria,
a stable indicator strain. In addition, the experimental and control
batches were analyzed for the presence of free bacteriophage in the medium
without preliminary incubation under optimum conditions .
Objects were prepared in similar fashion to study the combined effect
of vibration and irradiation under laboratory conditions . Vibrations were
produced on a vibration stand at frequencies of 35, 70, and 700 cps, with
an amplitude of oscillation ranging from . k to 0.005 mm and an accelera-
tion of 10 g, for 15, 30, and 60 minutes. GUBO Co 60 (dose 100 r, rate
21 r/min) was used as the source of gamma rays. Experiments were per-
formed both with combined and with separate exposure to gamma rays and
vibrations. In the case of combined exposure, vibrations were produced
l-l/2 to 2 hours before or after irradiation.
Results
In the flight experiments, induced phage production was investigated
kQ, 72, 96, and 120 hours after the spacecraft landed.
We evaluated the results of each experiment by means of an index R,
which is the value of induced phage production as compared with spontane-
ous production, and the Fisher-Student index of statistical reliability
(P). Analysis of the phage-producing activity of the lysogenic culture
E. coli K-12 (X.) exposed on Vostok 3 and Vostok h showed that the number
of phage particles in the experimental batches exceeded that in the con-
trol. In the batches exposed on Vostok 3, the number of cells producing
phage particles, observed k8 and 72 hours after the vehicle landed, was
3-5-^-6 times greater than in the batches left on earth.
i6o
Thus, the Vostok 3 and Vostok h experiments revealed that space
flight factors had an inducing effect on the lysogenic bacteria, E. coli
K-12 (x), as reflected in a tangible increase in phage-producing cells.
The inducing effect was much more pronounced in the Vostok 3 experiments
than in those on Vostok k, apparently because of a longer exposure to the
flight factors on Vostok 3.
As noted above, the inducing effect persisted for 48-72 hours after
landing, after which the level of induced phage production fell to that
of spontaneous phage production. This agrees with the results of a study
of the inducing effect of protons, which also persisted for a few days
after the action halted and then declined.
Our method is of value in determining the inducing effect of ionizing
radiation within the limits of 0.2-0.4 r. However, it does not follow
from this that the induction of lysogenic bacteria observed in the space-
craft experiments was caused by the aforementioned dose of cosmic radiation.
The inducing genetic effect may well have been caused by the combined
action of various space flight factors (vibration, acceleration, weight-
lessness, radiation).
Our investigations on the effect of vibrations ranging from 35 to 700
cps suggest that vibration is a major factor in the radiogenetic effect
recorded in the lysogenic bacteria.
Thus, the combined action of vibration and gamma irradiation followed
by vibration (simulation of flight conditions) intensified the biological
effect of the gamma rays almost twofold. However, no inducing effect was
observed in the experiments involving vibration alone. In the experimental
batches, the number of phage-producing bacteria did not exceed that in
the batches not subjected to any agent. This indicates that under flight
conditions vibrations probably exert a sensitizing influence, i.e., they
increase the sensitivity of lysogenic bacteria to ionizing radiation,
thus permitting ionizing radiation to have an inducing effect with doses
smaller than 0.2-0.4 r. This hypothetical explanation of the results
obtained requires experimental confirmation.
In conclusion, we wish to stress the importance of combined investi-
gations. It is particularly essential to study the effects of the various
components of cosmic radiation (protons, electrons, neutrons, heavy par-
ticles, y and roentgen rays) combined with the mechanical factors of space
flight.
161
MODERN GENETICS AND PROBLEMS IN SPACE BIOLOGY
N. N. Zhukov-Verezhnikov, M. N.- Volkov, V. I. Yazdovskiy,
I. N. Mayskiy, P. P. Saksonov, P. A. Konstantinov,
A. P. Pekhoy, G. P. Tribulev, N. I. Rybakov, V. Ya. Kop'yev,
I. I. Podoplelov, N. N. Dobrov, V. A. Kozlov, V. G. Vysotskiy,
N. S. Artem'yeva, V. V. Antipov, B. A. Mishchenko, Ye. D. Aniskin,
Ye. V. Yudin, K. D. Rybakova and R. I. Shupik
Some of our data on the genetic aspects of space biology have al-
ready appeared in earlier publications. This communication examines
three subjects : the current status of space flight genetic danger,
genetic basis of the search for drugs to provide antiradiation protec-
tion from hereditary anomalies during these flights, and some genetic
considerations in exobiological problems.
The first of these subjects can be examined in the light of new in-
formation derived from a genetic analysis of the offspring of the various
organisms that were carried on Vostoks 1, 2, 3, and h. To begin with,
we must say that the idea of using for this purpose a set of biological
objects on all levels of organization has been completely justified. If
the planners of the experiments had restricted themselves to a single
object, the results would have been one-sided. If, for example, only
insects (Drosophila) had been used, the launching data on the first
vehicle to return (the second Soviet spacecraft) could not have been
correctly interpreted. Ya. L. Glembotskiy, E. A. Abeleva, Yu. A.
Lapkin, and G. P. Parfenov at that time reported as follows: "Assum-
ing that the mutagenic effect (0.M+- percent induced lethals) noted in
mature sperm of the strain in question was caused by ionizing radiation,
the dose of this radiation would need to be approximately 1 40-150 rad...
The point nature of the induced mutations (20 affected cytologically)
and high rate of mutation of the spermatids as compared with that of the
spermatozoa indicate that they may have been caused by cosmic radiation. "
This applied to recessive lethal mutations. After the flight, a tangible
increase in frequency was obtained in regard to dominant lethal mutations,
too. If there had not been other biological objects on the same space-
craft, the aforementioned facts would have been a serious obstacle in the
way of determining the feasibility of the first manned space flight.
However, this spacecraft, as is known, carried various objects
(notably, lysogenic bacteria, which had a distinct genetic reaction to
O.3-I r) which made possible the introduction of corrections into the
data. The lysogenic bacteria showed no increase in the relative number
of genetic changes (measured by the number of phage particles produced)
as compared with cultures kept at the spaceport and under ordinary labo-
ratory conditions, making it obvious that the sharp increase in mutations
in Drosophila was not evidence of the presence (in the orbit) of any
%
162
radiations capable of exerting genetic influence. The effect in Drosoph-
ila was due to the way they were exposed, to biological characteristics
absent in man and highly organized animals, and to the individual cel-
lular and subcellular structures.
It is of interest to reflect that, if only lysogenic bacteria (as
the most sensitive objects) had been exposed in order to detect the
genetic efficiency of ionizing radiation, it would have been correct to
conclude that there were no genetically active doses of radiation in the
orbit. However , the significance of the combined genetic effect of vari-
ous space flight factors would have escaped attention. The result un-
doubtedly would have been the same as that obtained in investigating
Drosophila.
Comparison of the data gathered by various laboratories utilizing
the standard set of biological objects to study the aftereffects of space
flights suggests that undoubtedly certain factors are lacking in these
orbits which, by themselves, could significantly increase the relative
number of genetic changes in cells. However, the already identified
set of launching and flight factors have the potential for causing
genetic changes, the number of which exceeds in level the ground con-
trol. Subsequent flights (Titov, Nikolayev, Popovich) revealed that not
only Drosophila but also lysogenic bacteria can react to a fairly long
flight with an increase (albeit slight) in induced phage production,
i.e., with genetic changes.
These new observations are theoretical. The fact is Drosophila,
which cannot be secured on spacecraft like astronauts or be oriented to
the flight axis in a chest-back direction, might have manifested genetic
changes in response to mechanical stimulation of vibrations and accelera-
tions. The experiments with lysogenic bacteria imply that other factors
than vibrations and accelerations can induce genetic changes, however
slight .
Experiments simulating flight conditions (W. I. Rybakov and V. A.
Kozlov) revealed that exposure of these bacteria to a combination of
vibrations and Trays (100 r) followed by vibrations again almost doubled
the genetic effect of the y rays. However, the physical measurements
showed that completely effective levels of cosmic radiation were actually
lacking in the orbits. Thus, to account for the "effect of the lysogenic
bacteria" there is one more possible source of genetic effects that must
be carefully examined- -weightlessness .
The genetic effect of weightlessness should be studied independently,
since attempts to increase genetic changes in lysogenic bacteria by means
of vibration devices without irradiation were unsuccessful even when 700
cps were used. Since lysogenic bacteria have been observed to react only
to long space flights, these studies require sustained influences, and
16 3
one way to achieve these is "by the microcentrifuge system, which is still
in the planning stage. This system, which would generate accelerations
of 1 g, could provide gravity during space flights, the biological ob-
jects serving as a control for other objects in a weightless state.
Genetic analysis of their offspring would throw light on the effect of
weightlessness in, so to speak, a pure form, since all the other flight
factors acted on all the objects equally. While setting up the study
of the genetic effect of weightlessness as a new item in our program,
we should nevertheless not forget the necessity of examining the genetic
danger presented by cosmic radiation on new space flight routes. This
applies to vibrations and accelerations as well, especially when the
•launching of a rocket with acceleration is a protracted affair.
Thus, a team of Soviet biologists and physicians, by direct experi-
ments on spacecraft, was able to advance our knowledge of genetic danger
in space, thus ensuring the safety of the flights already made. This
research must be intensified in order to safeguard future flights, which
will be longer and, therefore, pose greater genetic danger. This makes
it essential to speed up the search for new preventive drugs, and the
second part of this paper will present some data on this area. It will
be recalled that chemical antiradiation protection has been based for a
long time on the search for drugs capable of preventing radiation sick-
ness or the physiological changes that precede it. The search for drugs
to prevent the development of genetic effects in offspring is not being
pursued as intensively as it should mainly because of the lack of a
biological model that could be used to furnish the primary characteristics
of prospective protective chemical substances.
In 1961-1963, N. N. Zhukov-Verezhnikov, M. N. Volkov, I. N. Mayskiy,
V. I. Yazdovskiy, A. P. Pekhov, P. P. Saksonov, N. I. Rybakov, V. A.
Kozlov, P. A. Konstantinov, and others suggested that lysogenic bacteria
be used for systematic selection of "antigenetic" substances that could
be given to astronauts. The reports presented by our team at this con-
ference contained detailed material on lysogenic bacteria as one of the
most promising models for the primary selection of such substances.
We should like to emphasize that drugs of this kind can be used for
other purposes than preventing radiation genetic injuries. Long-term
treatment of lysogenic bacteria with such compounds results in a block-
ing of the pathological information present in the DNA of these bacteria
and introduced therein by the so-called moderate bacteriophages. Such
treatment, to be sure, merely blocks rather than removes this informa-
tion because lysogenic bacteria remain immune to superinfection by the
corresponding moderate phage.
This opens up a new approach to the prevention of genetic anomalies,
especially those resulting from malignant degeneration of cells, which
are a transformation or mutation genetic process. We succeeded in
16U
achieving, more or less, the first "immunization" against pathological
genetic changes by a unique kind of "weakened genetic vaccine." In fact,
the analogy to immunization with live vaccines is striking. Just as a
weakened vaccine confers immunity without sickness, so does a fragment
of bacteriophage DNA brought into the genotype of the bacterial cell
confer immunity without at the same time being able to cause the produc-
tion of phage, which some investigators regard as a peculiar "malignant
disease of bacteria."
To digress, we may recall that our team has called attention to the
eventual possibility of providing "immunity" against cancer by such
blocked DNA molecules extracted from cancer cells. This is one of the
possible effects of nucleinotropic substances, which thus differ in
principle from antiblastic substances because they are directed not at
killing cancer cells (which also more or less threaten normal cells) but
at normalizing the genetic changes underlying the transformation of
normal into malignant cells or at preventing the very possibility of
such transformation.
In commenting on some medicogenetic problems in this paper, we wish
to stress that protection of astronauts from genetic injuries is one of
the main problems of modern genetics. It cannot be solved without going
into the most fundamental aspects of genetic information and control.
The Decree of the Central Committee of the Communist Party of the
USSR and USSR Council of Ministers mentions the necessity of learning
to control the processes of heredity and metabolism.
The need of genetic safeguards for space flights has stimulated a
number of investigations that have implications for more than space
biology. Making use of the most complex and effective modern research
techniques, they give promise of enriching other branches of modern
biology and medicine.
IMPAIRMENT OF PROTECTIVE MECHANISMS FOLLOWING EXPOSURE
TO AN ALTERED GAS MEDIUM
V. N. Zagryadskiy and Z. K. Sulimo-Samuyllo
On space flights man may have to function in an altered gas medium,
exposed to a host of unusual factors that will tax the organism's broad
capabilities for adapting. It is, therefore, extremely important, theo-
retically and practically, to study the physiological mechanisms of
165
compensatory reactions and impairment. Thus far, attention has focused
mostly on adaptability to low partial pressure of oxygen in the ambient
atmosphere. The capacity of the organism to withstand high concentra-
tions of carbon dioxide, which cause hyper capnia, and the factors that
promote the washing out of carbon dioxide from the body (hypocapnia) now
deserve serious study, since the disruption of homeostasis by hyper- or
hypocapnia cannot but affect reactivity to various space flight factors.
We and our colleagues recently made a comprehensive investigation
of the effect on human beings and animals of prolonged exposure to atmos-
phere containing low concentrations of carbon dioxide (from 1.5-5 percent)
with normal and high (about kO percent) oxygen content. We studied re-
sistance to lateral accelerations, breathing oxygen at excess pressure,
physical exercise, and high ambient atmospheric pressure (about 40° C).
The initial protective reaction of the body to a high CO^ content
of inhaled air consists of a substantial increase in pulmonary ventila-
tion through acceleration and, even more, through the deepening of res-
piration. This compensatory reaction is aimed at lowering the partial
pressure of CO in alveolar air and preserving the constancy of its
composition, and its effect is sometimes much greater than that required
by the altered composition of the gas medium. As a result, there is a
decrease in the CO content of alveolar air (hypocapnia) when the CO
content of inhaled air is 1.5 percent. These findings are in complete
agreement with the curves obtained from I. M. Sechenov's formula by
theoretical calculations based on the results of experiments. In
breathing gas mixtures containing 3-3.2 percent COp for 2-k hours, the
content and partial pressure of CO in alveolar air in man scarcely
changes. With CO concentrations above 3 percent, a progressive increase
in pulmonary ventilation does not produce the required effect and the
CO content of alveolar air grows .
After prolonged exposure to atmosphere containing up to 3 percent
CO (1.5-2 percent), the body is unable to compensate for the changes
in composition of alveolar air by an increase in pulmonary ventilation
and the latter decreases (inhibition of respiration) and C0 p in alveolar
air increases. Further adaptation is in the direction of pronounced
deceleration of the cardiac rate, decrease in oxygen utilization (P. F.
Vokhmyanin), drop in body temperature, and reduction in the activity of
the oxidative enzyme systems- -succinodehydrogenase and cytochrome oxi-
dase (N. D. Popov, P. T. Grabchak). This marked slowing of the vital
166
rhythm is a protective function designed to limit the production of COp
in the tissues. However, the protective nature of these reactions is
effective only in a state of relative adynamia.
Prolonged exposure to low concentrations of CO changes the nature
of the excitability of the respiratory and cardiovascular centers, as is
evident from the fact that comparatively slight muscular or emotional
tension, which causes some acceleration of respiration, is followed by a
disproportionately sharp and prolonged pulse acceleration. The cardio-
vascular center remains highly excited for many hours after the gas medium
returns to normal. At the same time, resistance to lateral accelerations
(T. N. Zheludkova, 0. Yu. Sidorov) and to breathing of oxygen at excess
pressure (P. F. Vokhmyanin) diminishes. Normalization of the metabolic
processes after prolonged exposure to high CO concentrations by increas-
ing the amount of oxygen in the gas medium or by administering enzymes
and vitamins increases resistance to the aforementioned factors. It has
been experimentally demonstrated that conditioning animals to hypoxia
and accelerations increases resistance to COp (Chzan Zhu-Go).
In our experiments, hypocapnia was induced in animals by enforced
hyperventilation for 1-2 hours. The C0 p content of the blood dropped to
12-17 percent by volume .
Apnea is the initial protective reaction to hypocapnia. However,
prolonged hypocapnia actuates the mechanisms that intensify the produc-
tion of COp in tissues. This is shown by the increase in oxygen utili-
zation and hyperthermia (Nguyen Lung). In hypocapnia, the rectal tem-
perature rises I.5-I.8 , muscular temperature rises somewhat less, brain
temperature rises least. These changes in temperature relations in
hypocapnia have a definite biological significance. At the same time
the vascular reflexes also change (V. leva). There are three groups of
such changes: (l) inhibition of pressor and depressor reflexes; (2)
inhibition of depressor and intensification of pressor reflexes; (3)
inhibition of pressor and some intensification of depressor reflexes.
In severe hypocapnia, the depressor vascular reflexes become dis-
torted. However, the aforementioned changes in the vasomotor reflexes
cannot be regarded as compensatory.
The concept of protective reflexes to ensure homeostasis and keep
the organism in equilibrium with the external environment emerges from
I. P. Pavlov's theories on self -regulation, wherein the CNS and its higher
divisions play a leading role.
167
Certain degrees of hyper- and hypocapnia impair CNS function and
not only disrupt the balance between the excitatory and inhibitory proc-
esses but reduce their strength and mobility. The result is inhibition
or impairment of the compensatory reactions aimed at maintaining homeo-
stasis. Investigations concerned with preservation and intensification
of the activity of the protective reactions are of great practical sig-
nificance under these conditions.
AN INVESTIGATION OF HIGHER NERVOUS ACTIVITY AND SOME MOTOR
REACTIONS IN MAN UNDER CONDITIONS OF BRIEF WEIGHTLESSNESSl
A. T. Zverev and L. A. Kitayev-Smyk
1. An investigation was made of (l) the speed of motor reactions
to stimulation of the first and second signaling systems, (2) the speed
and accuracy of motor reactions in performing very simple mathematical
operations (addition and subtraction), and (3) accuracy in working with
an indicator.
2. The subjects worked at a special panel, a box containing dif-
ferent colored bulbs and bulbs which when turned on caused figures to
appear on the panel. On this panel were numbered tables, a telephone
dial, and contacts, two injection needles of different diameters. Work
at the indicator with a fluorescent dial was done in a darkroom.
3. When a red blub lit up, the subject had to connect the contacts
and at the flashing of a 3-digit number- -dial the same combination of
figures with the telephone dial or toggle switches. In some flights, it
was necessary to add to or subtract from the given figure a certain num-
ber. In working with the indicator, the subject had to move a lever to
keep the arrow of the indicator, which was periodically deflected with
a special timer, in the center. In some flights, work was done with the
indicator when the subject was exposed to angular accelerations and
Coriolis accelerations created by rotation on a special armchair.
k. A total of I39 experiments was performed.
5. In working with the contacts, the time required by most of the
subjects (regardless of the degree of training) to execute the movement
decreased during the takeoff of the plane . It decreased even more during
1 Tbe method of producing weightless conditions is described in A. M.
Klochkov's report presented at this conference.
168
the initial acceleration but increased in the period of weightlessness,
frequently exceeding the original level. It decreased again after the
succeeding acceleration but increased during horizontal flight.
6. The changes in time interval from the time the toggle switches
were switched on until they were switched off were similar to the changes
in reaction time when working with the contacts .
7. The changes in length of the latent period when working with the
figures were more or less the same as the changes in time of the motor
reaction when working with the contacts and toggle switches .
8. The magnitude of the error made by the subject ( "error in work")
when centering the indicator arrow was 1 l/2-2 times greater during the
initial and succeeding accelerations than during horizontal flight. It
was 3- i4- times greater in the weightless period.
9. As a result of angular acceleration, the magnitude of the
"error in work" grew proportionately in all stages of the experiment by
10-15 percent.
10. Coriolis acceleration likewise caused the "error in work" to
increase in all stages of the flight, particularly in the weightless
period (8-10 times).
11. The resultant data were at variance with the subjective evalua-
tions of the persons tested. They noted in oral reports that it was more
difficult to work in the period of accelerations than in weightlessness.
However, objective recording of the speed and accuracy of their work
showed that the opposite was true.
12. The impairment of speed and accuracy of motor reactions observed
in weightlessness may be due not only to changes in the tonic relations
on the periphery, but to the development of inhibition in the correspond-
ing points on the cerebral cortex as a result of a change in the level
of proprioceptive afferent impulses in weightlessness.
169
SOME ASPECTS OF HEMODYNAMICS IN BREATHING OXYGEN WITH HIGH
PRESSURE IN THE LUNGS
D. I. Ivanov
Breathing oxygen with high pressure in the lungs is now very common
in aviation. It is the most widely used method of ensuring flight safety
at altitudes of more than 12,000 m. Many Soviet and foreign investiga-
tors have studied, the problem, and the characteristics of respiration
under such abnormal conditions may be considered fairly well known. The
nature of the ensuing functional changes suggests that two systems are
most involved- -respiration and blood circulation—especially the latter,
since the cardiovascular changes are most pronounced.
These changes consist essentially of a marked rise in arterial and
venous pressures, in the minute and systolic volume of the heart, and in
the amplitude and rate of propagation of the pulse wave through blood
vessels of the muscular type. Changes in EKG and, above all, in the
ballistocardiogram are characteristic. The EKG shows an increase in the
P wave, which most investigators regard as a sign of high pressure in
the pulmonary circulation. ' The shape and magnitude of the systolic com-
plex of waves on the ballistocardiogram change as do the relations between
them by phases of respiration, an index of hemodynamics in the pulmonary
circulation. Significant hemodynamic changes are also suggested by stasis
on the periphery, as evidenced by an increase in the size of the extremi-
ties. Analysis of the published reports and our own investigations
shows that the hemodynamic changes observed cannot be wholly ascribed to
the effect of high pressure in the lungs, for secondary circulatory
hypoxia plays a definite role in the process.
Despite the many studies of the problem, one of the most important
aspects, to our way of thinking, has been virtually ignored, namely, the
state of the blood flow--its linear and volumetric rate. In the past
few years the author and some his colleagues made some studies along this
line. One series of experiments- -using dogs in acute and chronic experi-
ments under ground conditions with different pressures in the lungs-
dealt with the rate of blood flow in the pulmonary circulation and utilized
the method of tagged atoms (D. I. Ivanov and G. G. Sturua, 1952). The
blood was tagged with radioactive disubstituted sodium phosphate, a
method of value in evaluating both the rate of blood flow and the func-
tional capacity of the right ventricle.
This series of experiments showed that breathing oxygen with high
pressure in the lungs decreases the rate of blood flow in the pulmonary
circulation while the time required by the "indicator tag" to blend with
the mass of circulating blood increases. We concluded that resistance to
the flow of blood increases in the lungs and that systolic emptying of
111 ii mi ii i
170
the right ventricle becomes less complete. The magnitude of these
changes varied with the intensity of the pressure created in the lungs,
the state (anesthesia) and individual characteristics of the animal.
The changes in blood flow become more intense as the experiment con-
tinued and severely impaired the hemodynamics of the pulmonary circula-
tion. A slowing of the blood flow in the pulmonary circulation took
place against a background of growing functional cardiac incompetence.
The use of special compensating suits employing the pneumatic prin-
ciple mitigates, but does not relieve entirely, the effect of high pres-
sure in the lungs. In experiments on intact (nonanesthetized) animals,
the results were about the same, although somewhat less pronounced.
A second series of experiments was devoted to local tissue blood
flow in man exposed to the same respiratory conditions as in the first
series (V. S. Gurfinkel', D. I. Ivanov, A. Ye. Ivanov, and V. B. Malkin,
1957)' This series also used the method of radioactive indication (Na„i ).
An isotonic solution of sodium bicarbonate with a total activity of 2-3
lie (in 0.2 cm3) was injected subcutaneously or intramuscularly. Keti's
method was used in the investigation. A curve showing the activity of the
artificially created "depot" was constructed in a system of semilogarithmic
coordinates .
The results of the investigations showed that an increase in pressure
in the lungs regularly altered the dynamics of tissue blood flow. With
breathing at a pressure of 20 mm Hg or more, the rate of local blood flow
clearly decreased in most of the subjects; it did so less frequently when
the pressure was 10 mm Hg. The external back pressure on the body,
created by the special suit, became less effective when pressure in the
lungs reached 50 mm Hg or more. The general direction of the curves
showing changes in the radioactivity of the "depot" and the identity of
the results in both series of experiments are grounds for believing that
the patterns of blood flow in the systemic circulation are reflected here
too. The intensity of the blood flow is the main factor in mobilizing
the "depot". Permeability of the vascular membranes does not seem to
play an important role in the process.
A third series of chronic and acute experiments studied the venous
blood flow while the animals were breathing oxygen with high pressure
in the lungs. The thermoelectric method as modified by M. Ye. Marshak
(V. G. Voloshin, D. I. Ivanov, A. N. Mazin, and V. I. Popov, 1952) was
used in the investigation. We found that the venous blood flow decreases,
the degree varying with the pressure in the lungs and the time, i.e.,
duration of the experiment. A temporary increase may precede the de-
crease. There were three phases in the coronary blood flow changes: a
171
rapid and substantial decrease, a relative increase, then a slower pro-
gressive decrease. The degree and nature of the decrease in coronary
flow was directly related to the speed with which pressure rose in the
lungs. Transection of the vagus nerves had little effect. No direct
relationship was observed between the coronary flow and magnitude and
direction of the changes in arterial pressure.
The metabolic processes play an important part in the mechanism
controlling the coronary flow, as demonstrated by our findings in ex-
periments with probing of the venous sinus, in which we studied not only
the blood flow but the arteriovenous difference in and amount of lactic
acid and glucose in the outflowing blood (V. G. Voloshin, D. I. Ivanov,
A. A. Kiselev) . In some experiments there was a decrease in the ar-
teriovenous difference in p with a simultaneous decrease in the coronary
flow and a markedly hypoxic EKG, suggesting the existence of a collateral
blood flow through the system of arteriovenous anastamoses. Special ex-
periments in which we employed the polarographic method showed that oxygen
tension in the myocardium changes with change in the coronary blood flow
while the temperature of the myocardium rises (V. G. Voloshin).
The external back pressure on the body, created by special "com-
pensating suits", mitigates, but does not entirely relieve, the effect of
high pressure on the coronary blood flow.
In a chronic experiment on an operated dog breathing oxygen with high
pressure in the lungs, the coronary blood flow changed in the same direc-
tion as in the acute experiment.
The relations that develop when breathing at high pressure at great
altitudes become more complex. At first the coronary blood flow may in-
crease considerably and then rapidly decrease to a very low level, re-
quiring immediate termination of the experiment. We observed a similar
picture in ground experiments involving the breathing of gas mixtures
deficient in oxygen. In breathing oxygen at high pressure under ground
conditions against a background of a low coronary blood flow, we likewise
noted at times a sudden increase followed by a rapid decrease to the
point of complete cessation.
This blood flow reaction under high-altitude conditions is apparently
due to the simultaneous action of two factors: high pressure in the lungs
and primary hypoxia (hypoxic). The latter seems to be the more signifi-
cant because it mobilizes to the fullest the functional reserves of the
organism, and in a short time manages to maintain the blood flow.
A point worth emphasizing is that the nature of respiration is one
of the most important factors that determine the level of venous blood
172
circulation in breathing 2 at high pressure. Superficial breathing or
temporary apnea when pressure is created in the lungs interferes with
the flow of blood to the heart and causes the flow to decrease even more.
It is quite possible that the initial phase of greater decrease in blood
flow may be due to the impairment of respiration associated with high
pressure in the lungs.
Our investigations show that breathing oxygen with high pressure
in the lungs brings about significant changes in hemodynamics, resulting
in circulatory hypoxia and marked changes in venous blood circulation.
CHANGES IN MAN'S PRINCIPAL PHYSIOLOGICAL FUNCTIONS AFTER
PROLONGED EXPOSURE TO LOW BAROMETRIC PRESSURE IN A
SMALL SPACE
D. I. Ivanov, V. B. Malkin, I. N. Chernyakov, V. L. Fopkov,
and Ye. 0. Popova
An extremely important aspect of space flight is the necessity of
remaining for long intervals in a small enclosed space under rarefied
atmospheric conditions and relative isolation from familiar daily sur-
roundings .
This study of the dynamics of man's principal physiological functions
sought to simulate the above-named conditions, by:
(1) Determining the possibility of man's remaining for a prolonged
interval (about 30 days) in a small chamber in a. rarefied atmosphere
corresponding to altitudes of 3000, 5000, and 7000 m with pOo ranging
from 150-200 mm Hg.
(2) Studying the nature and direction of the functional changes
brought about by disruption of the normal diurnal rhythm. When the work
started (l959)> only fragmentary data were available on these matters.
Investigations were carried out in a specially equipped pressure
chamber with a useful capacity of 5 m > and gas composition, temperature,
and humidity regulated by a regeneration unit. Each of two healthy
young men was assigned a daily regimen, which was alternated in subse-
quent experiments. Regimen No. 1, which did not vary much from the normal
173
(the hours of sleep were mainly at night--from O3OO to 0900--and only
1500 to 1700 during the day), was more favorable than regimen No. 2. In
the latter, the subject slept from 2O3O to O23O and during the day from 1200
to 1^00. While awake, subjects followed the experimenter's instructions
but spent their free time as they wished. An experiment lasted 10 to 30
days. Meals (k times a day) consisted of canned food and concentrates
with vitamins added. Feces and urine were collected in airtight containers
and periodically removed from the pressure chamber.
During the preparation and performance of the experiments we studied
the behavior and general condition of the subjects : EEG, EKG, respiration,
arterial pressure, body temperature, cardiovascular and respiratory re-
actions to measured physical exercise and breath holding, energy expen-
diture (by Haldane's method), etc. The EKG was recorded in the 3 stand-
ard leads; the EEG in unipolar and bipolar leads from the occipital and
frontal regions, then subjected to a frequency analysis. The general
EMF of the EEG and EMF of the individual rhythms composing the EEG were
also determined.
The physiological indices were recorded k times daily, the hygienic
indices 6 times daily. In all, we performed 6 experiments, lasting from
10 to 30 days, with 7 subjects.
Analysis of the data of the hygienic investigations showed that (l)
the pO in inhaled air fluctuated between 150 and 200 mm Hg, (2) pCO --
between 2 and 14 mm Hg, ( 3) air temperature in the pressure chamber--
between l8 to 27° C, (k) relative humidity- -between 30 and 75 percent.
The latter occasionally dropped to 10- 30 percent, at which time, subjects
usually complained of dryness in the mouth, nose, and throat. Epistaxis
was sometimes noted.
As mentioned above, barometric pressure in the chamber was maintained
in each case at a level corresponding to altitudes of 3000, 5000, or 7000
m. The rapid shift from ground to high-altitude conditions and subsequent
exposure to a rarefied atmosphere had no significant effect on the main
physiological functions: indices were usually within the control values.
For example, in experiment No. 1 (altitude of 3OOO m), P-n's pulse and
respiration fluctuated between 50 and 90 beats and between 10 and 23
respirations a minute, while the corresponding figures for P-v in ex-
periment No. 2 (altitude of 5000 m) were 52-76 beats and 12-20 respira-
tions and in experiment No. h (altitude of 7000 m) — 5^-73 beats and 12-
20 respirations. Approximately the same values were noted for the cardiac
and respiratory rates of these individuals in the control measurements.
No clear-cut relationship could be detected between the barometric
factor and the changes in the other physiological indices (EEG, arterial
pressure, body temperature, duration of apnea, energy expenditure, etc.).
17k
Analysis of the EKG, however, revealed a left-axis deviation resulting
from altitude meteorism.
Functional changes were more closely related to time spent at the
"altitude". For example, in experiments involving a 30-day stay, a
moderate but regular increase of 10-15 beats per minute was noted in
the cardiac rate, starting on the ll4-th-15th day. This rate was either
maintained or continued to increase, until the end of the experiment.
While performing the orthostatic test, during the first 10-15 days,
pulse rate rose by 10- 35 percent and thereafter by 50 percent. More-
over, arterial pressure was even higher. All these changes were par-
ticularly marked when subjects were awake at night (regimen No. 2).
The EEG at this time often showed a slight shift of frequency toward
the slow rhythms. Subject F-k, during the first half of the experiment,
exhibited considerable instability in the values of the recorded indices.
All these changes may be regarded as the onset of incipient fatigue
caused by prolonged exposure to the experimental conditions (Den-Su-I,
Ye. M. Sklyarchik, A. V. Korobkov).
The decrease in basal metabolism (by an average of 15-20 percent
below the original level), especially after a long stay in the pressure
chamber, is noteworthy. The marked decline in overall activity of the
subjects was most likely the reason for the decrease in gas exchange.
The nature and direction of physiological changes were largely de-
termined by sleep and relaxation routines. In regimen Wo. 1, the one
closer to normal, there was a distinct diurnal periodicity of functional
changes (pulse and respiratory rates, body temperature, arterial pres-
sure). The minimum value of the indices was usually noted during sleep
at night, the maximum, while awake in the daytime.
In the less favorable regimen (No. 2), the diurnal periodicity of
the functions studied not only leveled out, but often became distorted.
Pulse and respiratory rates and body temperature during sleep were some-
times faster than during wakefulness. The EEG invariably revealed dis-
tinct diurnal fluctuations of the frequency spectrum. However, in this
regimen, one could see the dominating frequency shift toward the slow
oscillations in the nighttime period of wakefulness. When the subjects
resumed regimen No. 1, disruptions of the diurnal periodicity of func-
tions were less marked.
The foregoing data point up the need of conducting special investi-
gations to find rational regimens of sleep and wakefulness for space-
craft crews. But we emphasize that the criterion for correct selection
of an optimum regimen should be the time of day set aside for sleep, not
merely the number of hours .
Analysis of our data indicates that a lowering of barometric pres-
sure to levels corresponding to altitudes of 3OOO-7OOO m with a partial
175
pressure of p in inhaled air ranging from 150-200 mm Hg has no signifi-
cant effect on the human organism. Prolonged (up to 30 days) exposure
to these conditions with adequate retention of physical fitness is quite
feasible. The observed functional changes are within physiological limits,
transient, readily reversible, and unrelated to the effect of rarefied
atmosphere.
In evaluating the condition of subjects, their resistance to prolonged
exposure to experimental conditions, and the regimen chosen, one must take
into account the nature of the changes in the diurnal periodicity of the
physiological functions .
We should like to conclude by noting that the main views emerging
from these investigations have been confirmed by the studies of A. G.
Kuznetsov, N. A. Agadzhanyan, and others.
HYPOXIA AND CHEMICAL THERMOREGULATION
K . P . Ivanov
Reduction of the partial pressure of oxygen below a certain level in
inhaled air suppresses heat production and lowers body temperature in
animals and man. The extent of the corresponding "critical" oxygen ten-
sion and degree of impairment vary with the ambient temperature, rapidity
with which hypoxia develops, type of organism, and several other condi-
tions (Lintsel, I93I; Shick, I9I+8; Slonim, 1952; Goebel et al., 1953;
Pichottska et al., 1955; Ivanov, 1959; others). Theoretically, this
phenomenon ought to be able to serve as a method of locating the sources
of controllable heat production in homoiothermal animals . From the
practical point of view, an investigation of this factor is essential
in selecting suitable temperature conditions for living beings in a
closed space with possible changes in the gas medium.
During the past 5-6 years we tried to determine the physiological
aspects of chemical thermoregulation and hypoxia, working principally
with skeletal muscles, which many investigators believe to be the main
source of controllable heat production (Tower, 1939; Hopfert, 1952;
Barton and Adholm, 1957; Chatonnet, 1959.
Gas exchange and certain forms of muscular activity (cold tremor,
"thermoregulation muscle tonus") were investigated simultaneously under
a variety of conditions. The muscles were studied with a highly sensitive
176
electromyography Changes in gas exchange and electrical activity of the
muscles in cold tremor and "thermoregulation tonus" were investigated
both in the whole animal and in individual groups of muscles.
We discovered that in rats and rabbits at an ambient temperature of
about 10-25° C a decrease in oxygen utilization during hypoxia coincides
with depression of muscle electrical activity (ivanov, 1959 J Ivanov and
Den-Su-i, i960). A more drastic suppression of gas exchange during
hypoxia occurs in relatively small animals (mice), in which, other things
being equal, "thermoregulation muscle tonus" is comparatively high
(ivanov, i960).
Gas exchange in rabbit femoral muscles in situ was determined in order
to make a more precise quantitative evaluation of the energy efficiency
of "thermoregulation tonus" and cold tremor as the physiological mech-
anisms of chemical thermoregulation. We found that "thermoregulation
tonus" increases oxygen utilization by the msucles 3O-I5O percent; cold
tremor, by 200-400 percent or more (ivanov, 1962). In rabbits and rats,
whose skeletal muscles constitute about one-half of body weight.
According to some indirect data (Motram, 1955 )? "the muscles when
the animal is fully resting take up about 3O-35 percent of the total
oxygen utilized by the organism in the absence of chemical thermoregu-
lation. Judging by these figures, the animal's energy balance may be
changed 40-50 percent in either direction solely by "thermoregulation
tonus" (weak electric activity of resting muscle). The significance of
cold tremor in this respect is even higher. Since in our experiments oxygen
utilization during hypoxia fell about 50 percent below the original level,
it is fair to assume that the resultant depression of "thermoregulation
muscle tonus" or cold tremor was the main cause of the general lowering
of heat production in the organism.
A positive correlation between suppression of electrical activity
of muscles and gas exchange during oxygen deficiency has been confirmed
by accurately recording, with an electronic integrator, the electrical
activity of various muscles. Statistical analysis of the integrator
readings indicated that peculiar qualitative changes in exchange like-
wise took place in the muscles during hypoxia.
While seeking the central mechanisms governing suppression of
tremor and "thermoregulation tonus", we found that the particular effect
is most likely unrelated to the general suppression of brain functions
caused by hypoxia. At the time these forms of muscular activity are
weakened, the electrocorticogram fails to reveal any specific changes
attributable to oxygen deficiency in the cerebral cortex. At the same
time, oxygen tension in the blood of the sagittal sinus of the brain
remains fairly high- -about 30 mm Hg (ivanov, I961).
177
It follows, then, that hypoxia may directly influence and inhibit
the central thermoregulatory mechanism. It is possible, however, that
suppression of the functions of chemical thermoregulation in hypoxia is
likewise due to dysfunction of the peripheral apparatus of temperature
sensitivity- -the cold thermoreceptors. The sum of impulses flowing to
the hypothalamus from the cold receptors of the skin, according to re-
cent information, is positively correlated with the peak of heat pro-
duction in the organism (Benzinger, 1962). On the other hand, as Dodt
(1956) showed, hypoxia decreases the frequency of these impulses. This
is obviously a matter that requires further research.
THE TIME RESERVE IN STEADILY DECREASING ALTITUDE
L. S. Isaakyan
1. The time reserve for remaining conscious at altitudes of 9 _ H
km (time from the moment of stopping the oxygen supply at a given alti-
tude or time of a rapid climb to an altitude without an oxygen supply
until syncope) has been fairly thoroughly studied by Soviet and foreign
authors (V. A. Skrypin, 1957; A - Khichkok, 1953; Barron et al., 1958;
others) .
2. It is now a matter of considerable practical importance to study
a somewhat different parameter- -the time reserve which ensures retention
of consciousness. It starts with the subject's reaching a given alti-
tude (effected in 3-7 seconds), continues until the appearance of the
earliest signs of oxygen deficiency, and includes a rapid emergency
descent to an altitude of Ik 5 km, started as soon as the first signs of
acute hypoxia appear .
Since one of the factors in development of acute hypoxia here (rate
of descent) is highly dynamic, we propose to call this parameter, in
contrast with the ordinary "static" time reserve (TR ,), the "dynamic"
time reserve in retaining consciousness (TR-, ).
Consequently, unlike TR , TR expresses the development of de-
st dyn
compensation of functions not only after exposure to hypoxia of con-
stant intensity but, even more important, after a swift change of this
factor in the direction of a decrease. The correlation between TR
dyn
and TR can be represented by the following equality :
178
TR^ ^ TR • (0.6-0.75) + X, where
dyn ~-' st
X is a time variable depending on the altitude at which the descent be-
gins, especially on the rate of descent (at a given altitude X is equal
to the time of emergency descent).
3. In designing experiments to determine the dynamic reserves in
dogs, we utilized--in judging development of a state equivalent to al-
titude syncope in man--these criteria: pulse deceleration of 50-80 beats
or more per minute in relation to the frequency measured after staying
5 minutes at the altitude; tonic and clonic spasms of the masseter,
tail, and extremities; inhibition of protective and orienting reflexes
in response to painful electrocutaneous stimulation and intense light
stimulation; reduction in voltage of the EKG waves, arrhythmia, change
in rate and nature of respiration, etc. We also assumed that the TR-,
could be roughly calculated from the empirical formula:
TR ~ TR • (0.6-0.75) + X.
dyn st
Thus, our task was to determine experimentally the approximate
values of the two parameters indicated in the formula (TR and X) .
So
k. Eighty-four control experiments were performed on 9 <iogs to
determine the static time reserve at 9, 10, and 11 km altitudes (TR . ).
The animals were raised to these altitudes in 1.5-2 minutes without
oxygen and kept there until the above-mentioned signs of acute hypoxia
appeared, after which they were given oxygen and "lowered" to the earth
in 2-5 minutes. An hour before the rise and during the action of acute
hypoxia, EKG, respiratory rate, reflexes, and skin temperature were re-
corded. External appearance and behavior were photographed on color
film in all the experiments .
The control experiments demonstrated that the animals ' static time
reserve at altitudes of 9> 10, and 11 km averaged 15, 31, and 56 minutes,
significantly, the relationships among these values are quite close to
those established for man. For example, the human reserve at 11 km
(3O seconds) in relation to the reserve at 10 km (60 seconds) is 1:2,
or the same ratio as in the dogs (l5.*3l)-
This has led us to assume that, despite the great differences be-
tween human beings and animals with respect to altitude resistance,
some of the biological mechanisms (if only temporary in nature) respon-
sible for the compensation and decompensation of functions in both man
and animals exposed to hypoxia have common features .
|Bf
179
Forty- seven main experiments were performed on the same 9 dogs to
determine the value of X for altitudes of 9, 10, and 11 km. The ex-
periments were run exactly as the controls, except that the emergency
descent to h.l km started as soon as decompensation of functions became
apparent. The time of emergency descent (t = X) was regarded as the
product of the mean value of the static reserve that we determined
(TR ) and the value of K, which changed in different experiments with
the same animals from 1 to 5 (X^t ^ TR C+ 'K, where K = 1-5) •
v em sx. '
These experiments show that a weakening of the signs of decompensa-
tion of functions during an emergency descent followed by their rapid
restoration may be achieved if the values of K for altitudes of 9, 10,
and 11 km are no higher than 2.5, 2.8, and 3.3, respectively. The values
of X , X , and X can be calculated from these values along with
9 10' 11 km
the dynamic time reserves (from the empirical formula TR, ^ TR •
J v ^ dyn st
( 0.6-0. 75) + X) corresponding to them.
5 . In view of the foregoing on the common time relations in the
development of acute hypoxia in dogs and in man as well as some other
observations and published data on the matter (abstract from Canadian
Aviation, No. 8, 1962), it is reasonable to assume that similar rela-
tions between TR , and TR exist in man too.
st dyn
EVALUATION OF THE DEGREE OF TENSION IN PILOTS EXECUTING
LANDINGS IN VARIOUS TYPES OF MODERN AIRPLANES UNDER
ORDINARY CONDITIONS
L. S. Isaakyan
1. According to observations of the State Civil Aviation Scientific
Testing Institute (Nil GVF), marked neuropsychic tension is noted in the
majority of pilots of Civil Aviation Fleet (CAF) transport planes dur-
ing the execution of landings ("on final") even under ordinary condi-
tions (i.e., simple weather conditions and smoothly working equipment).
The appearance of tension is without doubt an unfavorable factor
conducive to early fatigue and pilot error, and also determines the
degree of complexity of piloting a plane of a given type. From this
point of view, an evaluation of the degree of tension in pilots during
180
landings of various types of airplanes, even under ordinary conditions,
is of great practical importance both for rationalizing the work routine
of the flight crew (establishment of sanitary norms and distribution of
the flight load) and for the resolution of various other problems (wages,
constructive improvements in control elements, instrument panels, etc.).
2. The physiological mechanisms underlying the development of a
state of tension in workers during predominantly mental -emotional work
(this group includes pilots), have for a long time remained unstudied
despite the multiplicity of jobs of this kind. Interpretation of vari-
ous data permits the assumption that at the basis of these mechanisms
is an extraordinarily high excitability of cortical conditioned-reflex
communications in both signal systems, which are close to the critical
(pessimal) threshold, and are not grouped with a defined and stable
dynamic stereotype, and which work for the priority inclusion of new
or little reinforced communications during a simultaneous irradiation
of stimulation upon the hypothalamic structures and an intensive acti-
vation of the entire reticular apparatus of the central nervous system
(B. K. Gurvich (1959), Yu. L. Komendantov (1959), Yu. K. Petrov (1956),
Pshonik (1952), Morucci and Megun (19^9), A. M. Zimkina (1955), D. A.
Biryukov (l95l), Ye. N. Sokolov (1955), K. K. Platonov (1957, 1950),
N-. V. Golikov (1952, 1956 and 1957), L. L. Vasil'y ev and A. A. Knyazev
(1926), L. S. Isaakyan (1958, 1962), and others).
External tension in pilots during landing (on final) is character-
ized on the whole by the same features which, as in "negligible tension",
have been described in the reports of a series of authors (A. D. Ark-
hangel'skiy (193M, K. K. Platonov (19U8, 19^9, i960), Ye. A. Derevyanko
(19^9), and others). However, it has a number of peculiarities, which
includes a significant prevalence of vegetative functions (vasomotoric
reactions, shifts in arterial pressure, pulse, breathing, electroskin
resistance); and, sometimes, mimic components, a "residual" stimulation
of vegetative functions which depends on a number of conditions, occa-
sional phasic phenomena, etc. (M. P. Sheynin, V. V. Rassvetayev (i960),
L. S. Isaakyan, D. S. Kuleshov (1962)).
3. Taking into account the practical need for establishing a
methodology, which in the first approach and in a purely experimental
plan would make possible a comparative evaluation of the degree of ten-
sion in pilots at the time they are engaged in landing various types of
airplanes, this report, (which is based on observations and investiga-
tions of the State Nil GW and on some theses of technical cybernetics
and neurophysiology) attempts to plan ways to develop such a methodology.
U. A questionnaire using a special form (No. l) submitted to 100
pilots in various types of transport planes of the GVF showed that, from
a subjective point of view, tension at the time of an ordinary landing
l&L
(often perceptible, as a "sense of anxiety, of concentration, of in-
creased attention, of readiness to combat the unexpected, etc.") and
always expressed by definite shifts in the vegetative functions, will
depend on those physical efforts which must be applied to the control
units, on the speed of planning and of the ground approach, and on the
total time expended in completion of the landing during the on final.
Individual pilots indicate these and other factors as causes for
the tension- -the number of motors, the quality of the work and potential
of the braking system, the relation between the length of the landing
run of the plane and the actual length of the runway, the width of the
plane tracks, the reserve of fuel in the event a second circle is re-
quired, individual flying hours on a given type of plane, the presence
or absence of an inspector, etc. Since the first three causes occur
most commonly and are experienced more often than the others by pilots,
they were subjected to special study.
5. A study of recorded pilot exertions on the controls of various
types of planes, showed that the physical efforts of pilots at the "on
final" exerted on the control unit have a predominantly static character
(against the background of which, separate dynamic exertions appear);
both the static and the dynamic components of these efforts reach their
greatest value on the wheel during control with the elevator in the pe-
riod of piloting within a specific sector of the landing distance (from
a height of 25 meters to the point of touchdown on the runway).
That comparatively greater physical efforts in airplane control
exert a definite influence upon the development of tension can be under-
stood if we remember the difficulty of piloting an "inert" airplane,
the little-studied field of the relations between significant muscular
efforts and those physiological processes which characterize neuropsychic
tension, and, finally, the special role of static exertions with their
immediate reverse chemo- and proprioceptive afferentations in the central
nervous system which, to a greater degree than the interrupted afferen-
tation during dynamic exertions, are able to disorganize the normal work
of the cortical structures (V. V. Rozenblat (1958, i960), N. K. Verash-
chagin and V. V. Rosenblat (1955), and others).
Because registration of pilots ' efforts on the wheel, for deflect-
ing the elevator in the landing distance, is an element of the standard
method for testing airplanes, obtaining the quantitative characteristics
of these values for different types of airplanes was found to be possible.
Taking into account that the maximum of the exertions (even the very
rare use with the trimming tabs, which automatically "takeoff" exertions)
is observed as a rule during the 10 seconds before and after touchdown,
the total impulse of the static efforts (F, 't = P / , ) was
kg ti/kg/;
sec
182
calculated through a 20-second period as the area of the geometric fig-
ure formed "by the time base and the dynamic exertion pulse envelope.
The role of the second factor of the greater speeds of ground ap-
proach and landing in evoking tension is associated by the pilots with
the growing shortage of time for perception of the treatment of the in-
coming information and for the formation of adequate reactions.
Used for quantitative calculation of this factor (total quantity
of information- -I ) was the process which is widely employed in
pos
technical cybernetics, of computation of the amount of information as a
logarithm (on the base 2) of the value m, where m denotes the number of
possible answers to the given source of information (Hartley's Law).
Calculations for all types of airplanes were carried out on the basis
of a single orienting algorithm, expressed as a mathematical formula,
and which characterizes the most typical sequence of shifting of the
attention of the pilot and the influence on pilots of the landing
distance.
The role of the time required for landing, as a factor intensify-
ing the tension is evidently to be explained by the increase in the time
during which the pilot undergoes tension. This factor (time) was di-
rectly taken into account by us in the orientation algorithm in calcu-
lating the total quantity of information and was indirectly evaluated
by the intensity of those shifts in the vegetative functions (B) (ar-
terial pressure, pulse, breathing, skin temperature, electroskin re-
sistance, etc.) which could be registered in pilots on landing and were
expressed as mean values. Five of the mean values characterizing the
vegetative reactions of pilots on landing definite types of airplanes
were analyzed by us (for simplification) as factors equivalently influ-
encing the course of tension; they were expressed as single conditional
units of a calculation in which each unit has a value of 10, and, ac-
cording to the principle of the logical element "and", they were multi-
plied to form a product which reflects the resulting shifts in the vege-
tative functions (BP).
Undoubtedly, these vegetative- somatic shifts, which appear to be
secondary in relation to the primary mechanism of tension, have a stimu-
lating effect on the latter (A. M. Zimkina (1955); D. A. Biryukov (1951),
and others) .
Note: The possible range of changes in the maximal arterial pres-
sure (9O-I9O mm Hg), pulse (80-ll|0 beats/min), respiration (20-60
breaths/min) etc., was divided into 10 conditional units, the value of
one unit represented 10 mm Hg, 6 beats/min, h breaths/min, etc. Later,
all operations were carried out with conditional units (e.g., the ar-
terial pressure of ll+O mm Hg was expressed as 5 c.u., a pulse of 90, one
c.u., respiration of 1+0, two c.u., etc.).
18 3
Thus, three factors, which, according to the subjective evaluation
of the pilots, participate in the formation and stimulation of tension,
were presented as objective quantitative values, which characterize,
for each type of airplane, first, the total impulse of the static ex-
ertions of the pilot in moving the elevator in the course of the 20-
second period (P, .); second, the total quantitative information coming
in with respect to time to the pilot through his distance and kinesthetic
receptors (I ); and, third, the total shifts in the vegetative func-
tions (BP, arterial pressure, pulse, and respiration, skin temperature,
electroskin resistance).
The arbitrary, but necessary, assumption was made that all three
factors (P +i ^ I and BP) to an equal degree and according to the prin-
ciple of the sequential effect (the logical element "and") promote the
growth of the tension. This assumption permitted the expression of the
possible range of the values, P , . (100-600 kg/sec) and I (9OO-I5OO
" C1 pos
I.U.) by the same conditional units used in the resulting values of the
vegetative reactions.
A questionnaire on a special form (No. 2) for 78 pilots showed that
the different types of airplanes of the GVF can be arranged in a definite
order on the basis of the degree of complexity (tension) of piloting on
landing. Comparison of the indicated order with the three quantitatively
expressed factors characterizing the tension of pilots of various types
of planes in the landing distance showed that each of these blended
values directly, or, expressed in conditional units, on the whole repeat
the indicated order of complexity of piloting various types of airplanes.
This statement suggests the attractive idea of expressing the in-
tensity of neuropsychic tension of pilots in the landing distance by
some conditional units, which in an integrative form, would reflect the
quantitative level of each of the three factors, thus reflecting in some
way the degree of tension of the pilot in the landing distance.
In principle it seems not important which mathematical method will
be used to obtain this integrative index; it is important that this index
be proportional to each of the three factors. This can be accomplished
by adding them or multiplying them with subsequent logarithmization. The
latter way, possibly, is more correct as, it, first, uses the law (ac-
ceptable in our reasoning) of the cybernetic structure of logical systems
(all three factors operate on the principle "and" and, therefore they are
multiplied); second, it rests on the sufficiently supported law of Fechner
(1899), according to which a logarithmic dependence exists between sen-
sations (tension in the simplest sense may be represented as a complexly
181*
organized sensation) and the intensity of stimulation (Lazarev (19V7),
Weaver and Perron (1952), Weaver .and Lawrence (195M and others). This
dependence is expressed in the formula S = cln K, where S is the inten-
sity of sensation, c is the coefficient of proportionality, In is the
natural logarithm, and K is the value of the stimulus (Genetsinskiy,
Lebedinskiy (1956)). Considering, that the coefficient of proportion-
ality is unknown to us, while the natural logarithm is converted in
strict dependence with a more accessible index- -the decimal logarithm
(in N = 2.3 log N)--the integrative index of tension (S H ) can be rep-
resented by the following empirical formula :
S TT = log K, where K = BP-P. , «I
H t 1 pos
where all three values, BP, P. . and I are expressed in single condi-
ti pos
tional units of a scale graduated in units of ten. Both the weak and
also the positive features of the formula presented must be noted. The
former include an entire series of arbitrary assumptions, some of which
are either known to be inaccurate (e.g., the equivalence of the effect
on tension of the three factors BP, P.. and I ) or doubtful (e.g., are
' ti pos v '
these factors actually the leading causes of the development of the ten-
sion, or do more important ones exist); is it permissible to express these
factors in single units, etc.? The positive side of the formula is that
it permits a quantitative and, consequently, an objective presentation of
the subjective opinion of a number of the pilots regarding the complexity
of piloting in the landing of planes of different types. Furthermore,
the formula sets forth the possibility for further precision, since the
more that the problem is studied, the factors which form K, in particu-
lar BP, may increase without limit, and the integrative index of tension
(Stt) becomes more and more accurate.
SOME RESULTS OF A CLINICAL AND PHYSIOLOGICAL STUDY OF SENIOR
PILOTS OF THE CIVIL AIR FLEET
L. S. Isaakyan, D. S. Kuleshov, A. V. Chapek, V. M. Kozin,
A. N. Ustinova, N. M. Kulikova, Ye. I. Kuznetsova and
A. A. Shishova
The problem of age of transport pilots has practical and general
biological interest for aviation physicians and flight administrators.
185
Advances in technology are making it necessary to retain in the
Civil Air Fleet veteran, qualified pilots and to train personnel in the
handling of new and more complicated equipment. An important question
is how does age affect flying skill or mastery of new equipment.
References in the literature on this subject deal mainly with mili-
tary pilots. Some authors (Armstrong, Lomonako, and others) base their
prognosis of flying fitness on the psychological changes resulting from
age and occupational activity. Economic and safety considerations justify
retention of senior pilots as the most experienced and best qualified.
Experience and published reports reflect an inverse relationship between
the number of flight accidents, on one hand, and the flying hours and age
of the pilots, on the other.
To determine age-related pathology of flying personnel, we made an
analysis of the reasons for the disqualification of Civil Air Fleet
pilots :
(a) Cardiovascular pathology (mainly, atherosclerosis) --33. 6 per-
cent;
(b) Otolaryngological diseases--9.1 percent;
(c) Changes in vision--7.2 percent.
Results showed a direct connection between age and number of flying
hours and experience. No connection was found in 51-1 percent of the
cases between the age of pilots and any other pathology that served as a
reason for discharge. This group included diseases of the lungs, gas-
trointestinal tract, surgical, nervous, etc.
A group of CAF pilots were carefully examined in the hospital, with
a variety of clinical, roentgenological (and roentgenographic), labora-
tory (including biochemical), and electrophysiological methods. The
latter methods included electrocardiography, vectorcardiography, and
rate of pulse wave propagation. Special investigations were made of the
auditory, vestibular, and visual analyzers, higher nervous activity,
visual memory, capacity and concentration of attention.
None of the pilots examined had any health complaints and they re-
garded themselves as very healthy and physically fit. They continued to
fly before admission to the hospital and after they were discharged.
Results showed that the frequency of roentgenological, electro-
and vectorcardiographic changes in the heart and speed of pulse wave
propagation increased with age. Thus, roentgenological changes in the
heart could not be detected in any pilot under 35 years of age, but
were present in 61.3 percent of those in the 5O-5I1 year age group; changes
186
in the aorta were found in 7.1 and 77-^ percent, respectively. EKG
changes (decreased voltage of the waves, deviation of the electric axis
of the heart, impairment of excitability, slowing of atrioventricular
conduction) were almost twice as common in the older as in the younger
group. Propagation of the pulse wave was accelerated in all pilots over
50.
These results made it possible to diagnose incipient signs of athero-
sclerosis in h percent of the pilots under 35, but with increasing age
the frequency of atherosclerotic changes gradually increased.
A rough comparison of frequency of atherosclerotic changes with
published results of a special examination of males (people with ground
jobs and of the same age as the pilots examined) and the above-mentioned
reasons for pilot disqualification indicate that atherosclerotic changes
occur more frequently and at a younger age in flight personnel than in
persons employed in ground jobs, a phenomenon also noted by some foreign
authors .
In a functional test (20 squats in 30 seconds), extreme shifts in
pulse rate and arterial pressure were no more common in pilots over 35
than in the younger men, and both indices returned to normal within 3
minutes. This signifies that, in senior pilots, the adaptive mechanisms
of the cardiovascular systems to moderate physical exercise were at a
fairly high level.
The vestibular-autonomic and vestibular- somatic reactions of all
the pilots were at a fairly high level too, suggesting that the vestibu-
lar apparatus does not undergo unfavorable functional changes as a re-
sult of age or flying activity.
A decrease in auditory acuity at threshold values in the zone of
intelligible speech was noted in 23.6 percent of the pilots under 39, in
lj-l.it- percent of those in the kO-kS year group, and in 70 percent of those
50 and older. The degree of impaired hearing in these age groups aver-
aged h, 5, and 11 db, respectively. Individual variations in those over
50 sometimes came to 5O-9O db at different frequencies. The frequency
and degree of impaired hearing with air and bone conduction were more
pronounced in the pilots over 50 than in the younger men.
Auditory acuity decreased mainly at the high frequencies—beginning
with 2OOO-3OOO cps--as a result of noise, age changes, and, in a great
many cases, inflammatory diseases and injuries to the ear. However, in
the vast majority of cases, loss of acuity did not affect efficiency.
Testing acuity by whispering alone was insufficient, because it
fails to uncover defects in the range of sound perception frequencies.
187
Eyesight tests showed that night vision, color sensation, "binocular
vision, condition of the fundus ocili, and transparency of fluids were
normal in pilots of all ages. After kO, however, there was a weakening
of accommodation, as shown by removal of the nearest point of clear
vision to the degree of presbyopia. In such cases, correction by
glasses with an optical power of the order of two diopters and with bi-
focal lenses (for distant and close-up vision) adequately compensated
for the weakening of accommodation and permitted satisfactory performance
of duties .
Neurologically, there were no significant abnormalities, except for
very delicate changes in static coordination in pilots over k^> and under
30.
An investigation of higher nervous activity, the visual analyzer,
and some psychological functions showed that the mobility of the main
nervous processes decreased slightly with age while the stability of
the corresponding indices increased. The functions of higher nervous
activity reflecting the ability to change rapidly from inhibition to
vigorous action and to distinguish between similar stimuli were not ad-
versely affected by increasing age.
In pilots over h^> years of age with considerable flying experience
and many hours in the air, the indices of cortical excitability and
mobility tended to decrease slightly as the stability of the correspond-
ing indices declined.
Visual memory did not deteriorate with age, although the capacity
and concentration of attention tended to decrease slightly along with
high stability of these functions in the oldest pilots.
We concluded from our findings on Civil Air Fleet flying personnel
that age is chiefly a problem of cardiovascular pathology, changes in
visual function, and, in part, occupational changes in hearing. From
the practical standpoint, the problem can be solved by early diagnosis
of the commonest forms of atherosclerosis in its various manifestations
and stages (mainly coronary sclerosis), correct prognosis and expert
evaluation of efficiency, and adoption of preventive measures. There
is no reason to set up for CAF flying personnel any age limitations on
service suitability unrelated to pathology.
188
A THEORY CONCERNING GRAVITATIONAL INFLUENCES ON THE ORGANISM
P. K. Isakov
Adaptation reflects a quality of instability in an organism's in-
ternal environment. The range of adaptation to changes in the barometric
pressure of air, ambient temperature fluctuations, content of injurious
admixtures, partial pressure of oxygen in inhaled air, composition and
quantity of food ingested, and workload (rhythm, duration, volume, etc.)
has been fairly well studied.
The extraordinary progress of aviation technology has intensified
research on the effect of accelerations on the organism. This branch of
aviation medicine has now accumulated a large mass of experimental
material supporting the basic theory of functional changes consequent
to accelerations. To counter these changes a variety of preventive
measures have been devised.
The high speeds and altitudes at which spacecraft now travel- -bril-
liantly pioneered by the Soviets- -have made it necessary to study a
number of new factors, weightlessness in particular.
A fairly large amount of experimental material is now available on
various effects of partial or total weightlessness, but there, as yet,
no general theory to account for the mechanisms of weightlessness, just
as with accelerations. A unified theory is needed to explain the ef-
fects of accelerations and weightlessness on the gravitational field.
The phenomena of a static state of changes in body weight are not
encountered in man's normal environment nor likely to occur in any future
enrivonment. Both acceleration and weightlessness (partial or total)
almost always arise as a result of the dynamics of movement, which ex-
plains why living things are subjected throughout their lives to the
unavoidable influence of accelerations and weightlessness. Such changes
in body weight as may arise in the course of movement are, of course,
insignificant in degree and duration. But their frequency and syste-
matic quality are responsible for two kinds of influences on the body.
On the one hand, the changes in weight have a formative effect on the
morphological and functional structures. On the other hand, when the
body encounters other physical parameters of weight changes while active,
it tends to adapt. Naturally, both the degree and the range of adapta-
tion to accelerations and weightlessness differ. The latter is deter-
mined by the fact that during an organism's life cycle, accelerations in-
fluence morphology and function much more frequently than does weight-
lessness. Moreover, accelerations, unlike weightlessness, may achieve
multiple values .
189
The level of gas exchange, following acceleration, rises sharply,
depending on intensity. Reported in 1957, this has recently been con-
firmed by foreign investigators. The increase in gas exchange is un-
doubtedly due to the muscle tone change directed at maintaining the po-
sition of the body when its weight increases. Some responsibility for
the intensification of gas exchange and, consequently, the energy balance
of the organism is also attributable to change in the cardiovascular,
respiratory and other systems. There is also a similar relationship
between gas exchange and weight change in partial or total weightless-
ness. In both cases the conditions for the maintenance of body position
change from those that usually prevail throughout the life of the organ-
ism. Other reflexes of the muscular system are needed to maintain body
position and perform coordinated movements.
There are as yet no scientific data that indicate how soon the or-
ganism regularizes gas exchange after exposure to accelerations or
weightlessness, for the states of the organism investigated under these
conditions were relatively brief. Another reason is the marked duration
of transitional states in such experiments- -from acceleration to weight-
lessness and vice versa. Transitional states are, of course, conditions
that largely prevent establishment of a constant level of reflexes, in-
cluding that of gas exchange, as an integral index of the state of the
organism. Thus, there seem to be two prerequisites for determining time
required for adaptation to acceleration and weightlessness. First, the
periods of exposure to these factors must be much longer than the transi-
tional periods and, second, the intensity of acceleration must not be
more than double that which ordinarily prevails under ground conditions.
The second prerequisite stems from the need to maintain equality in the
effects of weightlessness and acceleration with respect to the degree
of changes in body weight as compared with those characteristics of the
ground surface .
The data presented in the table below illustrate the changes in gas
metabolism after exposure to weightlessness created during plane flights
along a ballistic trajectory (from G. F. Makarov's experiments). The
figures do not exhaust the full range of changes noted in the experi-
ments. In some cases, the differences in gas exchange in weightlessness
were smaller than those mentioned in the table.
Intake of Release of CO Pulmonary
Conditions 2 ventilation
(cm3 in l m ) (cm 3 in 1 m) (liters/m)
Ordinary 320 260 8.h
In weightlessness 533 I4.12 8.9
Period of aftereffects. . . 309 256 5.8
1
190
In other cases, a progressive lowering of the gas exchange level
in weightlessness was observed below that which followed the initial
exposure to this factor. It is important to note that oxygen utiliza-
tion and release of carbon dioxide were much more intense in weightless-
ness than in the original state.
The figures cited here apply, to be sure, to brief periods of
weightlessness lasting about 20-25 seconds. During this short period of
time the body is more or less adapting to the unusual change in weight.
How long does this state last? To what extent is it possible for the
level of gas exchange to become normal on further exposure to weight-
lessness? There are as yet no answers to these questions. Neverthe-
less, it is important from both the theoretical and practical stand-
points that they be found.
Turning now to the data characterizing the differential threshold
of perception of gravity, we wish to point out that the pattern observed
by Weber-Fechner changes after exposure to weightlessness and accelera-
tion. For example, the following occurs after acceleration: In esti-
mating the weight of objects with the arm immobilized at the elbow, the
subject tended to judge the weight accurately. When the weight was
determined with the entire arm, without immobilization the weight was
overestimated. Undoubtedly such fluctuations in estimations also de-
pend on the weight of the participating parts of the arm. A proportional
increase in the weight of these parts during accelerations complicates
estimation of weight. And the more the weight is increased when new
parts are included (hand, forearm, shoulder), the more the overestima-
tion.
Experiments under conditions of brief weightlessness confirmed
the relationship noted during exposure to acceleration- -the differential
threshold of perception of gravity decreases during weightlessness
(D. V. Afanas'yev's experiments).
The table presents the results obtained during immobilization of
the body and hand of the subject when the threshold of perception of
changes in gravity was determined by the first phalanx of the index
finger. The results were the same when the threshold was determined
with the entire hand, without immobilization.
It will be noted that in determining the thresholds of perception
of gravity with different parts of the extremities (finger, hand) and
Range of changes . ., , During a horizontal . ,., ma „
. & J _. B On the ground „ . , . In weightlessness
in exertion B flight
5ltO-650 r O.I3 0.13 0.09
191
Range of changes _ , n n During a horizontal _,_ . ...
7 . . ° On the ground „ n . , . In weightlessness
in exertion ° flight
778-945 r 0.11 0.11 0.09
under different conditions of immobilization of the arm (immobilization
of "the hand, forearm, without immobilization), the results of the ex-
periments were different. In other words, to obtain unambiguous results
it is necessary to make a special selection of the original values of
the changing exertions created by the device. The latter is due to the
difference in weight of the parts of the arm participating in the per-
ception of changes in gravity: the greater in weight of the part, the
greater must be the original level of the variable exertion. With a
further increase in the original level, there comes of course a time
when the observed relationship in the differential threshold of per-
ception of gravity is again disrupted. Our next task is to determine
the mathematical relationships between the weight of the parts of the
arm and the value of the original level of the exertion to be determined.
This will make it possible to determine the necessary exertions when
handling the levers in weightlessness.
The accuracy of movements in weightlessness, according to many in-
vestigators, is definitely related to the degree of adaptation to weight-
lessness. For example, in Beck's investigations, the greater the number
of experiments, the more accurately did the subjects execute the as-
signed movements. According to M. A. Cherepakhin, the number of hits in
the center of the target with arm movements in subjects adequately adapted
to weightlessness was 86 percent; they exhibited similar accuracy during
a horizontal flight. Just as in Beck's experiments, when visual control
was excluded, the accuracy of arm movements diminished. Analogous re-
lationships were also noted during the execution of assigned arm move-
ments.
A comparison of similar experiments performed in connection with
accelerations (V. V. Usachev et al.) reveals similar results. Change
in arm weight (in accelerations or in weightlessness) impaired the joint
function of the cutaneous and motor analyzers in estimating weight of
objects. The shorter the periods of these changes, the less possible
it was for ordinary correlations in the activity of the cutaneous and
motor analyzers to return to normal.
These considerations naturally do not exhaust the entire physio-
logical problem of gravity. It is far broader and deeper than the
aspects examined here. Understanding of the body's compensatory reac-
tions in a changing gravitational field will contribute extremely im-
portant, practical data and more accurate information concerning in-
dividual analyzers under normal terrestrial gravitation. Thus, a
192
solution of the physiological problems of gravity will also stimulate
efforts to clarify many aspects of pathology under normal conditions.
EFFECT OF HYPOKINESIA ON CERTAIN INDEXES OF EFFICIENCY
AND RESPIRATORY FUNCTION IN MAN
L. A. Kakurin, B. S. Katkovskiy, A. N. Kozlov and N. M. Mukharlyamov
This investigation studied physical fitness of man under prolonged
conditions of limited motor activity. Strict bedrest with persons re-
maining horizontal was selected as the experimental model. Resultant
motor, circulatory, and respiratory disorders were assumed to be caused
by hypokinesia and hydrostatic blood pressure.
Four healthy males, 21-2.K years of age, remained horizontal in bed
for 20 days, with motor activity at a minimum, even when eating or being
examined. Once every 3 or h days they were allowed to sit on a bedpan
for 10-15 minutes. The experiment was monitored by physicians and tech-
nicians on duty round-the-clock.
Before and after the experiment, the subjects were given physical
exercise tests (on a Belau apparatus) consisting of 100 climbs on a
step 25 cm high for 5 minutes to the beat of a metronome (work rate
I4-OO-5OO kg/min). While the subjects were in bed on the apparatus, a
spirograph measured oxygen utilization and other respiratory indexes
at rest. The following indexes were studied:
(1) Oxygen utilization, release of carbon dioxide, minute ventila-
tion, and coefficient of oxygen utilization at rest.
(2) Excess (above the resting level) increase in oxygen utilization
during physical exercise and in the restoration period (oxygen debt).
(3) "Restoration coefficient" (RC)--the ratio of the increase in
during exercise to the oxygen debt. According to F. Belau (l959)> A - D.
Damir and M. V. Pyatnitskiy (1961), P. Ye. Lukomskiy (1962), and others,
an increase in the "RC" coincides with general improvement in man and,
conversely, a decrease in this index indicates a deterioration of physi-
cal fitness.
(k) Index of work efficiency--oxygen consumption in ml per kg of
work.
193
The results are presented in the table below, the figures being
combined for the 1* subjects.
Indexes
Before the
experiment
1
l*
7
10
21*55
2391
21*19
2U28
21*1*7
3372
1*1*33
31*30
3567
3360
883
1787
1082
1157
938
3.91
2.56
3-^7
3.21
3.62
1.73
2.59
I.87
1.95
1-75
Work in kg
Increase in when working
P
in ml. . . .
Oxygen debt in ml . . . .
"RC"
Ml of o per kg of work.
It is evident from the table that oxygen utilization (index of
energy expenditure) during exercise increased from 3372 to 1*1*33 nu -
(3l.lt- percent) on the first day after the experiment, while the oxygen
debt increased by 102.1 percent (from 883 to 1787 ml). Individual fluc-
tuations in increase ranged from +6.7 to +1*2-5 percent; in oxygen
debt--+6l.5 to +I37. 3 percent. On the following days, the 2 utilization
increase during exercise was virtually the same as at. the beginning, but
the oxygen debt, by the l*th day of restoration, was 22.5 percent higher,
with individual fluctuations ranging from +I5.3 to +1*1-3 percent. By the
7th day, it was 31 percent higher and, on the 10th day, 6.2 percent higher.
On the 10th day of the restoration period, oxygen debt was below the
original level in only one subject (by 8.9 percent); for the other
three, it ranged above the original level by 8.5 to 20.2 percent.
The "restoration coefficient" decreased after the experiment by
3l*-5 percent (from 3.9I to 2.56); individual fluctuations ranged from
-22.5 to -1*2 percent. In no subject--even by the 10th day--was this
index completely restored.
After the experiment, there was a marked increase in the energy
value of a unit of work. Oxygen consumption per kg of work on the first
day of restoration was 1*9-7 percent higher than before the experiment
(from I.73 ml of /kg to 2-59 ml of /kg) . Individual fluctuations
ranged from +20 to +66.8 percent. On the l*th day after the experiment,
this index was equal to the original level in only one subject, but
6.3 to 18.7 percent higher in the other three subjects. On the 10th day
19^
of restoration, the mean index of work efficiency was close to the
original level (l.l percent higher). It was lower in two subjects (by
2.3 and lU.l percent) and higher in two (by 6.5 and 16.3 percent).
In bed, the subjects tended toward decreased oxygen utilization.
On the first day of restoration, oxygen utilization increased noticeably
in all subjects while resting (sitting), but from the 4th day on, no in-
crease in oxygen utilization was noted in those maintaining the same
position.
After 20 days in bed, physical exercise involving 100- step climbs
required much more effort than before the experiment: this personal
evaluation of physical deterioration was confirmed by increased oxygen
utilization during exercise, marked increase in oxygen debt, and de-
crease in the "restoration coefficient". Significantly, these indexes
were not fully restored during the first 10 days of restoration .
The oxygen utilization decrease while in bed suggests a reduction
in metabolic rate. The energy increase on the first day while sitting
was apparently the result of adaptation to the horizontal position and
impairment of hemodynamic processes.
Increased cardiovascular and respiratory demands during exercise
correlative with the functional deterioration of these systems (increase
in oxygen debt and decrease in the "RC") after prolonged hypokinesia
imply that the tolerance of maximum "stress" loads on these systems
and, in particular, the tolerance of overloads may be low.
Findings
1. Twenty days in bed cause marked deterioration of human physical
fitness--partly from hypokinesia and, in part, from body's adaptation to
a horizontal position.
2. Deterioration of work efficiency after remaining in bed makes
heavy demands on the cardiovascular and respiratory systems.
OBTAINING VISUAL INFORMATION DURING INSTRUMENT FLYING
I. A. Kamyshev
To obtain visual information during instrument flying, we employed
a method devised by K. K. Platonov that made use of synchronous recording
195
of readings of piloting instruments, and the pilot's glances and han-
dling of the controls. Various elements were tested by Popov, Pikovskiy,
Petrov, Derevyanko, and others, but synchronous recording of the above-
mentioned parameters proved impossible. The visual axis was interpreted
in this study by a new modification of the standard method.
In 1960-1962, 31 flights on a TL trainer were carried out by 13
pilots to test this method and to study some of the matters connected
with instrument flying, namely :
(1) Characteristics of control in pitch and banking;
(2) Relationship between reading of instruments and flying experi-
ence;
(3) Placement of piloting instruments.
According to data obtained on a UTI-MIG-15, a pilot handles the
controls 90 percent of the time--even on a steady horizontal flight, the
simplest mode of operation- -and yet cannot prevent deflections. In in-
strument flying, the average number of separate glances is 86 a minute,
i.e., every 2 seconds the pilot looks at 3 instruments. At times, the
glances number 150 or even 200 a minute, i.e., every second the pilot
looks at 3 instruments. These facts make it possible to describe the
work pace and time deficit quantitatively. Largest effort is concentrated
on the control stick in the right hand : pushing the stick to one side,
causes the plane to bank and change course; moving it toward or away
from the pilot changes altitude and vertical speed.
Characteristically, when changing course or banking, the pilot
focuses on the AGI (fighter airplane gyro horizon) and GIK. For ex-
ample, in going into a turn he looks at the AGI 7^- percent of the time,
but in pulling out of a turn he looks mostly at the AGI and GIK (86 per-
cent of the time in pulling out). While handling the control stick, he
controls the effect of the movement instrumentally, and as soon as the
readings of the instrument are at a given figure, he moves the rudder
to pull out. As a result, he accomplishes the desired bank in a single
maneuver.
However, this concentration on one or two instruments adversely
affects the control of the other parameters and is thus a possible cause
of unnoticed deflections, e.g., in altitude or speed. Such deflections
are particularly dangerous at low altitudes, as when coming in for a
landing .
The eye movements of 6 pilots in 16 circlings on the TL were filmed
from the place that the TL went into the 4th U-turn up to the inner hom-
ing radio beacon. We found that while making deflection shifts on the
•a
196
landing course and circling according to the 0SP-U8 (instrument-landing
equipment) system, the pilots looked at the AGI and GIK 88. h percent of
the time, but in circling according to the SP-50 system, they looked at
the AGI, GIK, and PSP 97-6 percent of the time. Thus, only 11.6 percent
(OPS) and 2.h percent (SP-50) of the time remained for checking on alti-
tude, speed, variometer, and tachometer.
Intervals between reading the altimeter, variometer, and speedometer
were 2U, 19, and 18 seconds, respectively. There were periods when
none of the instruments was checked for 15-17 seconds. It is very likely
that most plane crashes in the vicinity of homing radio stations are
due to the fact that the pilot in making deflection shifts in line with
the strip focuses for correction purposes on the AGI and GIK and thus
fails to note loss of altitude and speed.
The advantages of the bank control system are speed and efficiency;
its serious shortcoming is the required concentration on one or two
instruments, which thereby jeopardizes the craft. When changing the
vertical speed and altitude, the pilot cannot correct his movements by
the method described above because the variometer and altimeter have a
lag of about 3-I1 seconds. The control stick is shifted late so that
information from these instruments cannot be used to introduce correc-
tions in the executed movements. The pilot makes the desired change in
several tries : after moving the rudder, he must wait until the variom-
eter arrow comes to rest at some division. Meanwhile, if the vertical
velocity is not what is desired, a new movement has to be made, etc.
This method of control is inefficient and time-consuming.
Comparison of control longitudinal and transverse axis controls
shows that, even though both concentrate on a single lever- -the control
stick- -their systems of instrument indication are different. Thus, the
pilot is forced to use a variety of control methods, which increases
his difficulties in handling the plane. Further research should be
undertaken in the design of optimum systems of indication.
Subjects included pilots with varying experience in instrument
flying and persons with no flying experience but who had distinguished
themselves in handling the trainer. This made it possible to correlate
the reading of instruments with flight experience. It was found that
the more experienced the pilot was, the briefer was his glance, i.e.,
the less time he required to read the instruments. For example, the
average time veteran fliers required to check the speedometer was 0.6
second as compared with 1 second by the nonfliers. Consequently, it
would seem that experience increases the ability to read instruments
quickly so that a great many parameters can be checked in a given unit
of time and a mass of information obtained. By what means is the in-
strument reading time shortened? What processes can be trained for this
purpose?
197
It is well known that on the ground the time required (O.3-O.I1- sec-
ond) to read an instrument ( tachistoscope) is not affected by training
and is approximately the same for fliers and nonfliers. During flight
the reading process is not limited to perception of the instruments,
but each instrument ' s readings must be correlated with those of other
instruments, the previous readings, the flight mission, etc. In effect,
they merge with the central dynamics of analysis, synthesis, and gen-
eralization of information received. Here is the likely source of the
increase in the average amount of time spent in glancing at piloting
instruments. The fact that experienced men require about 0.6 second as
compared with the 1 second required by nonfliers indicates these proc-
esses are dependent upon training, and can, therefore, present a dif-
ficulty for pilots. To achieve the same effect under ground conditions,
we must reproduce through technical means the dynamics of instrument
reading and pilot movements.
It will be noted that we failed to observe a single instance in
which the pilots acted in accordance with the simple or complex reac-
tions that have been studied in detail in the laboratory. Even when a
man noticed an unexpectedly large deflection, the time from the moment
that he glanced at the instrument until he adjusted the control stick
accordingly (latent period) averaged 1.99 seconds. During this time he
usually checked 1 or 2 instruments affected by the deflection (e.g.,
altimeter, variometer, speedometer).
Moving pictures of eye movements made possible a new approach to
the problem of placement of piloting instruments. They should be
arranged according to their importance : the instrument that is looked
at most frequently and longest is of greatest importance and should,
therefore, be in the most convenient place. The moving pictures assigned
chief importance to gyro horizon, which may be checked 35 to 70 percent
of the time, depending on the mode of flight operation. The relative
position of the other instruments around the gyro horizon is determined
by the number of glances at each pair of piloting instruments . The
problem can be solved mathematically on the basis of these data by using
linear programming. This way of arranging the instruments guarantees
minimum angular movements of the eyes in the instrument flying.
%
198
REACTIONS OF ASTRONAUTS TO BRIEF PERIODS OF WEIGHTLESSNESS
I. M. Kas'yan
This research, was carried out on a two-seater airplane, in which
weightlessness lasting 35-U5 seconds could be produced, and on a labo-
ratory airplane with weightlessness lasting 20-25 seconds. Intensities
of accelerations and weightlessness were recorded on X and Y axes accu-
rate to 0.01 unit. While executing a parabolic trajectory, accelerations
of 1.5 to 3.5 + 0-5 units were attained for 10-15 seconds. The intensity
of acceleration in producing weightlessness did not exceed 0.02 to 0.07
unit on the Y axis or 0.02 unit on the X axis.
Each flight included 3 to 6 periods of weightlessness ( "vertical
climbs"), and intervals between "vertical climbs" were 10 to 15 minutes.
During flight, the astronauts were either fastened by straps to a spe-
cial chair or remained free and unfastened to move about as they wished
through a "floating basin" under weightless conditions.
Bioelectric activity of the heart (EKG), arterial pressure, pulse
and respiratory rates, and muscular strength of the hand (dynamometry)
were recorded during flight.
Coordination of movements in weightlessness was determined by a
"writiv 1 '- test", work on a special coordinograph, and free movement in
the ■ : rg basin".
,,,e no.... . _e and degree of change in finely coordinated movements in
weightlessness were studied by means of the "writing test" both when the
men were fastened to the chair and in the course of free "flight" in the
basin.
The recordings showed that when the astronaut was made fast to tn<=
chair, brief weightlessness had no effect on handwriting. In most cases
of free movement in the "floating basin", he was unable to write down
the assigned text.
In the coordinograph study, the astronaut followed a special pro-
gram with a metal pencil, making successive contacts in 5 sockets on
the device. These tests made it possible to compare the varying amounts
of time spent -in executing purposeful motor reactions before the flight,
during exposure to accelerations, and under conditions of low ■ aightless-
ness.
Results on the coordinograph showed no impairment of movements,
but revealed that the duration of the test varie.T luring different
flight periods .
199
Throughout the parabolic flight, the astronauts functioned effi-
ciently, rhythmically, and with no noticeable impairment of coordina-
tion. Coordination of movements was evaluated also from results of
tests taken during free movement in the "floating basin".
Analysis of the motion pictures and visual observations showed that
the astronauts were able to move about the "basin" only when assisted by
tightened ropes or by pushing against the side of the cabin. Without
such assistance, purposeful movement through a "floating compartment"
is not possible.
No significant loss of accuracy occurred carrying out prescribed
movements (turning the body to the right, to the left, around a longi-
tudinal axis, front and back somersaults, etc.) with open and closed
eyes in free movement in the basin. Although the astronauts, in the
first "vertical climb", showed some wariness, tension, and constraint,
in later "vertical climbs", they were able to keep the body position
steady, to move about smoothly and without constraint, to move with
greater efficiency and coordination. It is of interest that individual
characteristics were significant in purposeful motor acts in weight-
lessness.
Also interesting was the fact that facial coloring, after the first
"vertical climb", was not the same: it was quite pale in A. G. Nikolayev,
but very red in P. R. Popovich. This reflected individual differences
in autonomic-vestibular and emotional reactions to weightlessness (ef-
fect of the "novelty", etc.). These reactions were more pronounced
during the first parabolic "vertical climbs" than during the later
ones .
The fact that accurate movements can be carried out in weightless-
ness made it possible to provide a considerable assortment of natural
food products (solid, semisolid, and liquid). These included sandwiches
with smoked sausage and ham, meat patties and cabbage, grapes, pastry,
chocolate, etc. Analysis of the frames of the films and visual observa-
tions showed that it is possible to eat all kinds of food freely and
with no difficulty in swallowing.
Indexes of muscular strength, which was evaluated by manual dyna-
mometry with free movement in the "floating basin", showed marked de-
terioration in weightlessness- -by 5-8 kg and k-f kg for the right and
left hand, respectively.
The rate of respiratory movements on earth before flight ranged
from Ik to 2k cycles per minute. Accelerations of up to 3.5 units
(before and after weightlessness) caused in Yu. Gagarin and G. Titov a
slight increase (6-8 cycles per minute) in respiratory rate followed
by normalization under weightless conditions . And, conversely, during
I II I III II I I I I I I I II I III I I III I I Mill I I
200
exposure to accelerations, respiratory rate in A. Nikolayev and P.
Popovich scarcely changed, with an acceleration of 3-7 cycles per min-
ute in weightlessness.
In all the astronauts, the cardiac rate on the ground before takeoff
ranged from 5^-9^ beats/min. Acceleration produced a marked increase of
20-63 beats/min, but in weightlessness there was generally a slowing of
the pulse by 16-66 beats per minute. However, in some cases (Nikolayev)
it failed to reach the original values (during one "vertical climb" it
was above the original level), while in others it was even below the
original level .
Maximum blood pressure during accelerations rose by 10-28 mm Hg.
Minimum pressure fluctuated within narrow limits and showed no regular
changes. As the pulse accelerated in response to accelerations, the
R-R interval on the EKG shortened. The intervals of the P-Q and Q-T
complexes in most cases became somewhat shorter, while the amplitude
of the waves changed within the limits of physiological fluctuations.
In weightlessness there was a tendency for the EKG intervals to return
to normal .
Changes in physiological indexes during all phases of the parabolic
flight were functional in character and gave evidence of the body's
considerable compensatory and adaptive resources.
Besides the above-described investigations, a study was made of
sensory reactions, during weightlessness, on the basis of each astro-
naut's subjective evaluation of his condition and feeling. P. R.
Popovich described his condition during the experiments as follows :
"With free movement in the "floating basin" in the first "vertical
climb", there was some awkwardness and strain. In the second climb, I
felt better and was able to orient myself and coordinate my movements.
I turned 5 times around the horizontal axis of the body with eyes open
and closed. In the next climbs, moving in the "floating basin" was
pleasurable, etc."
In the course of familiarization-training flights on airplanes,
Yu. A. Gagarin, G. S. Titov, A. G. Nikolayev, and P. R. Popovich suc-
cessfully carried out the planned program and thereby demonstrated their
fitness and emotional and mental stability to cope with weightlessness.
577
201
PATH0M0RPH0L0GICAL VISCERAL CHANGES IN ANIMALS AFTER ACCELERATIONS
M. I. Kas'yanov and G. P. Mirolyubov
Since the landing of a spacecraft is accompanied by a shock overload
(acceleration), a study of its effects on the organism is pertinent.
Studies on pathomorphological visceral changes in animals throw some
light on the mechanism of the injurious factor and along with physio-
logical and biomechanical data help explain the effect of accelerations .
The familiar works on visceral injuries resulting from impact (Rotmar,
Green, and Ringsley, 19M5; Rashmar, 19h"J; MacDonald, Kelly, and Key,
1914.8; Step, 1958; M. A. Brestkin, G. A. Komendantov, V. V. Levashov,
et al., 19^9; S. A. Gozulov, and P. K. Isakov, 19^9; E. V. Marukhnyan
and I. A. Tsvetkov, 1950; others) had different objectives and conse-
quently are not completely relevant to the problems involved in ensur-
ing safe landings. This report presents the data from two series of
comprehensive investigations of landing impact.
In the first series with a single exposure, 20 animals (l8 white
rats and 2 dogs) were examined morphologically. The accelerations re-
corded in the experiments with the dogs and rats amounted to 35 and
IOO-870 units, respectively. All the experiments involved accelerations
in a "back-chest" direction, except in the case of 3 rats where the
direction was the reverse or "chest-back". Two rats were injected sub-
cutaneously with hexenal before exposure. Three rats died within an
hour after exposure--2 as a result of marked pulmonary edema (hexenal
poisoning), 1 as a result of hemoperitoneum. The other animals (15 rats
and 2 dogs) were sacrificed with ether anywhere from 5 minutes to 11
days after exposure. Immediate effects of accelerations included organ
injuries (ruptures), focal hemorrhages without rupture of the organs,
and fat embolism. Focal hemorrhages were noted most frequently in the
lungs (19 animals), less so in the pia mater and medulla. Hemorrhages
into perinephric tissue (2 out of l8 rats) and subcapsular hemorrhages
in the spleen (in 1 of the 2 dogs, but in none of the rats) were very
rare.
Transcapsular and subcapsular lacerations of liver tissue followed
exposure to 1+00 units or more and were found in 11 out of the 20 animals.
Rare injuries included transpleural laceration of the lungs in 1 rat
and subcapsular lacerations of kidney tissue in 2 others. Different parts
of organs were injured, depending on the direction of the impact through
the abdominal and thoracic wall (hemorrhages in the ventral portions of
the lungs when the animals were on their belly, hemorrhages in the
spinal prevertebral portions when they were on their back), on organs
striking against firm structures (skull, spine, thoracic ribs), and on
organs striking against each other. In the last case, of particular
importance are the heavy, firm organs, such as the liver and heart, and
"jrj-
202
the hollow organs with their contents (stomach, intestinal loops, uri-
nary bladder). For example, the left lobes of the liver, which are the
most frequently injured, are found between the heart and the stomach.
In dogs, moreover, close to these lobes is the firm spleen. And the
right central lobe of the lungs strikes against the heart while the
bottom of the lower lobe of the right lung hits through the diaphragm
against the liver, resulting in planar hemorrhages along the diaphragmal
surface of the lung. Fat embolism was found in the lungs of only 2 rats
(355 and 870 units).
In the hemorrhages and portions of injured tissues, changes regu-
larly developed in the form of erythrocyte disintegration, resorption
of the hemorrhages, and disintegration and resorption of the detritus.
Reactive processes, mainly productive in nature, were clearly evident
in the lungs and liver 3-U days after exposure. Degenerative changes
in this series of animals were noted in the ganglion cells of the brain
and cerebellum. Ischemic changes in these cells were very common,
acute swelling and disintegration of the cells, less common. These
changes were found in some animals within 15 minutes of exposure, but
regularly appeared toward the end of the first day. They were directly
related to the intensity of exposure and length of life thereafter.
Degenerative changes in the ganglion cells of the brain and cerebellum
appeared sooner and after less intense action in the dogs than in the
rats and with equal overloads they were more numerous. These degenera-
tive changes were apparently part of the picture of brain concussion
observed in the animals (tiny focal hemorrhages in the medulla, ischemic
changes in the blood vessels and capillaries, changes in the ganglion
cells) and they were directly caused by the accelerations.
The second series of experiments involved 7 dogs subjected to re-
peated (3-27) accelerations of varying intensity ( 35-300 units). The
animals were killed with ether at different times after the experiments
so that it was possible to trace the development of the processes over
a period of k-2k days. The average time between exposures ranged from
several minutes to 1-2 days.
All phenomena appearing in the first series were observed also in
the second series. However, owing to the repetition of the accelerations
and longer life of the animals after the first impact, all changes were
more pronounced than in the animals of the first series. Repeated ac-
celerations gave rise to new hemorrhages and new foci of damaged tissue,
as revealed by dissection and histological examination. The same animal
had injuries and hemorrhages of different kinds, depending on the time
they originated. Subcapsular hemorrhages in the spleen of 3 out of the
7 dogs were a feature of this series. The reason seems to be the con-
siderable firmness and weight of this organ in dogs. None of the l8
white rats in the first series was found to have any hemorrhages in the
spleen. On the other hand, none of the dogs had hemorrhages in the kid-
neys or perinephric tissue, as was the case with some of the rats.
203
The animals of this series had more pronounced reactive prolifera-
tive processes in the brain (focal and diffuse proliferation of glia),
liver (histiocytic proliferation in the foci of injury), and, above all,
in the lungs. Foci of atelectasis were observed in the lungs with a
thickening of the interalveolar septa as a result of histiocytic prolif-
eration and thickening of the collagenous fibers and bronchiolization
of the alveoli; foci of bronchopneumonia were also found. In all 7 dogs,
there were many more degenerative changes in the cerebral and cerebellar
ganglion cells than in the first series. The morphological picture of
brain concussion that followed the first impact was maintained by the
subsequent trauma, when degenerative changes originated in new groups
of ganglion cells . The changes were superimposed on the preceding ones
so that on the basis of the morphological picture they constituted a
traumatic disease of the brain.
New and what might be called destructive changes not observed in
the first series appeared in the lungs and kidneys of the animals in
the second series. These consisted of liquefaction of the mucosa of the
large bronchi and disintegration of the wall of medium- and small-
caliber bronchi into fragments followed by complete liquefaction of
the bronchi, caused mainly by degeneration of the elastic tissue of the
bronchi. Attenuation of the elastic tissue and fraying of its fibers
were also noted in the interalveolar septa. In the kidneys, the glom-
eruli were destroyed with liquefaction of the capillary walls, shrink-
age of the endothelial cells in the capillaries, and hyper chromat ism
of the endothelial cells. These changes were observed in all dogs but
one, which died of focal bronchopneumonia apparently unrelated to the
accelerations . The above-described destructive changes were undoubtedly
trophic, pathogenetically related to the degeneration of the ganglion
cells of the brain, chiefly the brain stem.
Summary
1. The accelerations used in this investigation caused tissue
injury and hemorrhages in organs, fat embolism, and a morphological pic-
ture similar to that of concussion of the brain together with degenera-
tive changes in the ganglion cells.
2. Traumas and focal hemorrhages developed in different parts of
the organs, depending on the direction and intensity of the acceleration,
on the striking of organs against the wall of cavities (skull, spine,
throax), and on their consistency and relative position. The firm and
heavy organs (liver, heart, stomach, intestinal loops, urinary bladder,
and, in dogs, spleen) are of particular significance.
3. Reactive changes around the injured areas and focal hemorrhages
as well as destructive changes in the lungs and kidneys required some
I
20U
time to develop and become evident. The destructive changes were prob-
ably trophic and related to degenerative CNS changes.
k. In cases of repeated exposure (official variant of landing),
unlike a single emergency landing, the possibility of cumulative ef-
fects as a result of repeated microinjuries stresses the need to reduce
the permissible limits of accelerations on landing.
QUANTITATIVE EVALUATION OF OPERATOR IN A "MAN-MACHINE" SYSTEM
Yu. V. Kiselev
A great many complicated technical systems are now in existence,
one component of which is the human operator. Such combinations are
called "man-machine " systems .
Man's involvement in such systems gives rise to many problems,
one of which is reliability. Reliability of a system is its ability
to perform assigned functions dependably and with ease of repair. If
reliability is to be increased, its precise quantitative evaluation is
essential.
No single criterion of reliability- -a characteristic by which it
can be judged quantitatively, applicable to all objects, devices, and
systems--has yet been found. Therefore, several criteria are now
used, the commonest being the probability of trouble-free operation of
a component or system over a given period of time.
Unfortunately, this criterion because mechanical failure and an
"operator" failure are different in nature, is not applicable to the
"human component . " The breakdown of a machine can generally be re-
paired only by intervention from without, whereas spontaneous restora-
tion of normal functioning is characteristic of the operator.
As in the case of the machine, it is impossible to select a cri-
terion of reliability for the operator that would apply to all situa-
tions in life. This paper will examine the quantitative characteris-
tics of the reliability of an operator performing a tracking task in a
closed or open cycle in a semiautomatic control system.
For this task, the best criterion of operator reliability in a
continuous process is the probability that with correct input data the
parameter of operator output will be within permissible limits at any
205
moment of working time; in a discrete process, the probability of cor-
rect performance of each cycle of operations.
Operator reliability cannot be practically evaluated without a
quantitative expression of the quality of the operations performed by
man. An empirical curve of distribution density of the parameter in
question is constructed on the basis of the measured quantitative values
of the operator output parameter. In doing so, it is well to regard
as the operator output parameter the operator error, i.e., the differ-
ence between what the operator actually puts out and what he should put
out.
The area under the distribution curve bounded on the left and on
the right by the maximum permissible values of the operator output
parameter, determines numerically the reliability of the operator
in the particular aspect.
The criterion of reliability examined means that it determines the
average relative portion of working time during which the operator out-
put parameter is within permissible limits- -in the case of a continuous
process--and the average relative portion of correctly performed opera-
tions—in the case of a discrete process. Operator reliability thus
calculated can serve as a starting point for setting up time norms.
TRACE PHENOMENA IN THE CENTRAL NERVOUS SYSTEM AFTER PROLONGED
OPTOKINETIC STIMULATION
V. A. Kislyakov and V. P. Neverov
Experiments were performed on rabbits to determine the characteris-
tics of optokinetic nystagmus (OKN) after prolonged (1-1/2 hours) opto-
kinetic stimulation. The optokinetic stimulus was a cylinder 2 m in
diameter with 22 black stripes 5 cm wide on the inside. OKN was re-
corded by the electro-oculographic method. Statistical processing of
data revealed significant decrease in OKN frequency in most of the
animals .
If, after l-l/2 hours of continuous optokinetic stimulation, a
dark screen that blocked the sight of the stationary cylinder stripes
was placed in front of the rabbits' eyes, the animals developed nystagmus
in the direction opposite to the OKN. This phenomenon, which we called
"reverse postoptokinetic nystagmus" (RPN), lasted 10 minutes. Subse-
quent experiments showed that traces of optokinetic stimulation may
$1
SI
206
persist in the CNS for a long time, manifested as RPN after 30 minutes
and, in some cases, after 1 hour. These findings were obtained in ex-
periments in which there was a delay in setting up the screen corre-
sponding to these periods of time. A delay in the RPN indicates pro-
longed CNS retention of trace excitation, the latter having no effect on
the motor neurons of the eye muscles . We performed other experiments
to determine the relationship between RPN and the rate of the preceding
optokinetic stimulation.
A series of experiments in which the animals were revolved a long
time in such manner that they could see the surrounding objects showed
that phenomena similar to RPN can arise in the CNS even after exposure
to ordinary visual objects of stationary surroundings. After the re-
volving chamber is darkened, they show up in the form of prolonged
nystagmus directed to the side opposite the rotation. The nystagmus
is intensified by additional vestibular stimulation.
We concluded from the foregoing that RPN, which is characteris-
tically directed to the side opposite OKN, is caused by the prolonged
circulation of excitation in the brain structures. These properties
of RPN make it possible to regard the phenomenon as a physiological
model for studying the neural mechanisms of illusory reactions.
CHANGES IN ELECTRIC ACTIVITY OF THE CEREBRAL CORTEX AND SUBCORTICAL
FORMATIONS IN ANIMALS EXPOSED TO BRIEF PERIODS OF WEIGHTLESSNESS
AND ACCELERATION
A. M. Klochkov
1. Quite a few reports have recently been published dealing with
the effect of weightlessness on human beings and animals. Most of the
reports are clinical and physiological in nature, and include a descrip-
tion of the symptoms of vestibular and autonomic impairment and record-
ings of the main physiological functions (Ward et al . , 1959 j Stutman
and Olsok, I960; Grovelin et al.; Greybiat and Clark, I96I; Beck, 1962;
others). There have also been, in response t6 the practical require-
ments of aviation and space medicine, a large number of physiological-
hygienic investigations of physical fitness and coordination of move-
ments in weightlessness (Geratewohl, 1957; Geratewohl et al., 1958;
Geratewohl and Ward, I96O; Gazer, I96I; Beckman, I96I; others). How-
ever, other recent reports are detailed studies of the physiological
mechanisms of the phenomena observed in weightlessness (King, 196l;
Shock, I96I; Reynolds, I96I; others).
207
As for investigations of changes in CNS bioelectric activity in
weightlessness, there are only isolated reports (Fiorica et al., 1962;
Grandpere et al., 1962). This communication describes the data obtained
in a study of changes in the bioelectric activity of different parts of
the brain of animals exposed to brief periods of weightlessness and
acceleration .
2. Weightless conditions were created by plane flights along a
parabolic trajectory. Each period of weightlessness lasted 25- 30 sec-
onds, and was preceded and followed by accelerations (l.8-2g) lasting
12-15 seconds. In some cases, weightlessness without preceding or
following accelerations served as a control.
Experiments were performed on two cats and one rabbit- -kept in a
screened cage- -with chronically implanted surface and embedded elec-
trodes. The biopotentials were derived in unipolar and bipolar fashion
by means of a single- channel a.c. amplifier with recording on a loop
oscillograph. The animals generally were nonanesthetized, except in a
few instances when cats were lightly anesthetized with pentobarbital
sodium.
Electric activity was recorded in the following regions of the
cerebral cortex: (l) anterior portion of the suprasylvian and ectosyl-
vian gyri, thought to be the site of the cortical projection of the
vestibular function (Anderson and Hernandt, 195^J Michael and Ades,
195^; Ruwald and Snyder, 1956), (2) visual zone, (3) orbital zone.
Electric activity in the subcortical formations was recorded in the
anterior hypothalamus and medial and lateral geniculate bodies.
3. A partial amplitude analysis of the bioelectric activity of
the cerebral cortex revealed that the magnitude of the changes after
exposure to brief periods of weightlessness and accelerations differed
from zone to zone. The most characteristic and pronounced changes were
found in the cortical projection of the vestibular function and in the
anterior portion of the suprasylvian and ectosylvian gyri.
Changes in electric activity in this zone followed this pattern:
With the accelerations preceding weightlessness, the electrocorticograra
showed evidence of pronounced desynchronization with increased frequency
and decreased amplitude of the oscillations, which persisted until ex-
posure to weightlessness. The amplitude of the oscillations grew during
the first 5-7 seconds of weightlessness and there was a marked shift
toward the slow waves (as compared with the electrocorticogram during
the horizontal part of the flight). Instability of the main rhythm of
the electrocorticogram and the presence of mixed waves was characteristic
of the period of weightlessness. For a period of 25- 30 seconds, the
high-amplitude a-like waves were followed several times by a frequent
low-amplitude wave, and vice versa.
208
These changes in electric activity occurred, although less pro-
nounced, also in the visual cortex, especially after exposure to the
accelerations. The effect of the latter on the electrocorticogram was
more extensive and uniform in different regions of the cortex, whereas
in weightlessness changes in the electrocorticogram were sometimes
absent. For example, in the orbital cortex (projection, p. IX), ac-
celeration was followed by indistinct desynchronization of the rhythm,
but after weightlessness the picture of the electrocorticogram was
virtually the same as that recorded during the horizontal part of the
flight .
At the moment of transition from weightlessness to acceleration,
a matter of 1-1. 5 seconds, there was a regular burst of high- amplitude
a waves lasting 2-3 seconds. They appeared somewhat less frequently
during the transition from normal weightiness to acceleration and at the
moment of transition to weightlessness. Thus, all the transitions from
weightiness to weightlessness and vice versa were characterized by the
appearance of a group of high -amplitude a waves, caused apparently by
the effect of the angular accelerations that take place during the
transition from one state of weightiness to another.
h. During derivation of the biopotentials from the subcortical
centers (hypothalamus and medial and lateral geniculate bodies), elec-
tric activity was relatively resistant to weightlessness and accelera-
tion. In the cases where there were changes in the bioelectric activ-
ity, they differed from those in the cortex. Acceleration tended to
increase the number of slow high -amplitude oscillations or produce a
picture of mixed waves, i.e., the desynchronization characteristic of
the cortex did not occur here.
In weightlessness, the amplitude of the rapid oscillations (lh-l6
cps) increased and there were almost no very rapid or slow oscillations,
i.e., here too the changes differed from those in the cortex.
What must be considered a peculiar reaction of the subcortical
centers is the fact that the above -de scribed changes did not take place
at the very moment that gravity changed . Rather, they developed com-
paratively slowly and the picture of the preceding period persisted for
3-5 seconds after the change in gravity.
5. All the above-described changes were most pronounced in wakeful
animals. In the experiments involving the use of light pentobarbital
sodium anesthesia, the changes were approximately the same, but much
less pronounced.
6. A comparison of the ordinary and control regimens showed the
same changes in both cases, but more pronounced when acceleration came
first, i.e., preceding acceleration intensified the changes that took
place in shifting from normal gravity directly to weightlessness.
209
7- Our data showed that brief periods of weightlessness and ac-
celeration induce CNS changes, the cerebral cortex being the most re-
active, for its electric activity changed to a greater extent and did so
more rapidly and regularly than in the subcortical centers .
The occurrence of pronounced and regular changes in the anterior
portion of the suprasylvian and ectosylvian gyri is additional evidence
in favor of the view of Anderson, Michael, Ruwald, and others that cor-
tical representation of the vestibular function is found in this area.
The precedence of acceleration is not a serious technical hindrance
to investigation of the effect of weightlessness on the organism. A
negative feature of the method is rather the brevity of the period of
weightlessness, which makes it difficult to investigate the slow-acting
processes.
SOME SENSORY DISTURBANCES IN PERSONS EXPOSED TO WEIGHTLESSNESS 1
L. A. Kitayev-Smyk
1. Observations were made of a group of subjects exposed, for short
periods of time, to weightlessness and recordings were made of sensory,
autonomic, motor, etc., reactions. Special methods were used to investi-
gate visual disturbances, ataxia, and changes in kinesthesia and time
perception.
2. Most of the subjects with little flying experience developed
various spatial illusions at the start of weightlessness--a sensation of
falling down accompanied by fear, sometimes quite pronounced throughout
the period weightlessness, by illusions with no particular emotional
coloring of being in a position with head down, on the chest, on the
back, on the side, or by an illusion of climbing.
3. Those who initially had sensations of falling and fear developed
in weightlessness the illusion that visible objects or parts thereof
were moving, getting larger, dissolving, or bending. Some observed a
violet halo around luminous objects. A study of light sensation in
weightlessness revealed a heightened perception of colors, chiefly yellow.
For a description of the method of creating weightless conditions, cf .
A. M. Klochkov's report to this conference.
210
Visual acuity at the start of weightlessness tended to decrease, but
after a while, in some of the subjects, became normal or heightened.
The visual reactions may have been caused by impairment of the integra-
tive processes both in the centers and on the periphery of the visual
analyzer, particularly by the decreased tone of certain eye muscles
(rectus oculi inferior, rectus oculi lateralis, and ciliary).
h. Ataxia was investigated by means of "horizontal writing" and
"diagonal writing" tests and by evaluating the results of aimed fire.
In "horizontal writing" (the drawing of a horizontal row of crosses
or other objects) the subject's hand slanted upward in weightlessness
but downward in acceleration with eyes open or closed (to a lesser
degree). If vision was not excluded, but the subject could not see the
hand with which he was drawing, then it slanted downward in weightless-
ness but upward in acceleration, i.e., the result of the "elevator
illusion". A similar reaction occurred with the eyes closed if the
subject held on with his left hand to the board on which he was writing
with his right hand. The "elevator illusion" generally did not occur
in subjects with flying experience.
The results were about the same in "diagonal writing", i.e., draw-
ing objects at a U5 angle to the vertical.
With aimed fire, the places of the hits shifted upward and to the
right in weightlessness, downward in acceleration. The accuracy of fire
decreased in weightlessness.
5. Changes in kinesthesia were studied by determining the accuracy
with which the subjects performed prescribed muscular exercises. In
weightlessness, less exertion was required by the nonfliers, but often
more exertion was required by the fliers. The tone of the arm muscles,
as determined from the maximum exertion, decreased in all subjects in
weightlessness, to a greater degree in the extensors.
6. Changes in time perception, judged from the accuracy with which
the subjects estimated a given period of time, were noted in weightless-
ness.
7. It is evident from the foregoing that weightlessness may impair
the functioning of various sensory systems in man. Elucidation of the
underlying mechanism requires further research.
211
THE BODY POSITION (POSTURAL REACTIONS) OF ANIMALS IN WEIGHTLESSNESS 1
L. A. Kitayev-Smyk
1. Interference with the interaction of the motor, vestibular, and
visual analyzers is undoubtedly the cause of the motor disturbances noted
by several authors in human beings subjected to weightlessness. How-
ever, the mechanism of these processes and the role of the individual
analyzers are obscure. Our investigations were undertaken to throw
some light on these matters.
2. The behavior of various animals- -fish, birds, and mammals
(white mice, white rats, guinea pigs, rabbits, cats, and dogs--was
studied during brief periods of weightlessness. We found that at the
onset of weightlessness fish lose ability to orient in relation to the
"top" and "bottom" of the aquarium. Birds demonstrate a motor reaction
resembling "continuous upward flight", followed in the 2nd or 3rd period
of weightlessness by calm suspension in a characteristic position with
wings spread back. Mammals show high motor activity.
Motor reactions of the mammals all showed "running" elements, but
there were individual variations from species to species. Thus, in mice
and rats--rotary motion of the tail; in rabbits--drum,ning movements
with the front paws. As adaptation to weightlessness developed, motor
excitation disappeared and muscle tone changed. Motor excitation per-
sisted longest in white mice and rats (through 8-10 periods of weight-
lessness) and disappeared soonest in dogs (2nd to i|th periods of weight-
lessness). In cats, the time required for adapting to weightlessness
varied from animal to animal.
3. We investigated the effect of excluding visual and vestibular
analyzers on behavior of rabbits and time they took for adaptation to
weightlessness. Exclusion of vision markedly lengthened adaptation time,
while motor excitation persisted through 20- 30 or more periods of
weightlessness. Unilateral labyrinthectomy gave rise to cyclical move-
ments, with "running" elements that caused the animal to turn toward
the destroyed labyrinth. Unilateral exclusion of the labyrinth pre-
vented adaptation to weightlessness. Exclusion of vision had no effect
on the nature of the reaction in the unilaterally labyrinthectomized
animals. In bilaterally labyrinthectomized animals, before developing
ground visual compensation of lost functions, motor reactions in weight-
lessness showed no tonic reactions and were practically the same as those
For a description of the method of creating weightless conditions, cf .
A. M. Klochkov's report to this conference.
212
of intact animals. The bilaterally labyrinthectomized rabbits with
acquired visual compensation did not exhibit motor excitation in weight-
lessness, but after vision exclusion, excitation appeared after a latent
period of 1-3 seconds and was more intense than in the intact animals.
Animals with excluded vestibular and visual analyzers failed to adapt
through 20 or more periods of weightlessness.
h. We investigated in rabbits and cats "the residual vestibular
sensation", the nature of the "turning" reaction, and the reaction to
progressive movements. To determine the occurrence of a "vestibular
afterimage", the animal with excluded vision was made fast at the trunk
and head with back down. At various intervals of time after the start
of weightlessness, the animal was let go and the "turning" reaction
observed. Upon release, this reaction occurred no later than 5 seconds
after the start of weightlessness.
Turning in weightlessness may have been due to the visual adjusting
reaction with paws reaching toward the nearest surface regardless of
whether it was the floor, wall, or ceiling. With turning of the trunk
in weightlessness, the head of an intact animal lagged behind the trunk;
it did not lag in a labyrinthectomized animal. When the animal in
weightlessness with previously turned head was released, the head re-
mained stationary in the intact animal and the trunk kept turning until
it was in a straight line with the head; in the labyrinthectomized ani-
mal, the head turned with the trunk stationary.
If the animal was released in weightlessness after a rapid turning,
it exhibited movements that turned it in the opposite direction. This
reaction was observed throughout the period of weightlessness (about 30
seconds) and was intensified by excluding vision. Thus, the "turning"
reaction in weightlessness can occur during the first few seconds under
the influence of a "vestibular afterimage."
We failed to observe any reaction to progressive movements in cats
and rabbits in weightlessness.
5. The occurrence of general excitation and heightened motor
activity in various animals in weightlessness indicates this factor is
an adverse stimulus primarily affecting the vestibular apparatus, with
vision the decisive factor in developing adaptation to weightlessness.
It has been established that the CNS also influences the organization
of these processes. Shock demonstrated that motor activity decreases
in cats after removal of those cortical areas where representation of
the vestibular function is localized. Gazenko, Grigoryan, Kitayev-
Smyk, and Klochkov found that removal of the cerebellum in cats pre-
vents adaptation and sharply increases the tone of the spinal and
occipital muscles and extensors of the extremities in weightlessness.
Grandpere et al. described several EEG changes in rats in weightlessness.
213
EFFECT OF CENTRIFUGAL ACCELERATIONS ON THE VENOUS OUTFLOW
IN THE CEREBRAL BLOOD VESSELS OF ANIMALS
V. Ya. Klimovitskiy
1. Of all the factors in intracranial hemodynamics, venous blood
flow may be the most sensitive to accelerations. In investigations of
this condition during flight, experimental models of impairment of cere-
bral blood circulation in centrifugal accelerations are essential, de-
spite their limitations .
2. In continuous experiments with rabbits, venous outflow was
investigated in the anterior sagittal sinus and major veins on the sur-
face of the brain.
3. Blood flow (volumetric flow rate) was recorded by means of
temperature- sensitive elements consisting of a microthermal resistance
and heater placed on both sides of the blood vessel. A calibration
curve for the temperature-sensitive elements was constructed in an acute
experiment on the femoral vein of a cat and on the model. Thermograms
were recorded either with a special apparatus with an independent power
supply set on the centrifuge or through a commutator on stationary re-
cording devices of various kinds. Heat was supplied by releasing fixed
(in current and time) heat impulses in the heater of the temperature-
sensitive element. As a consequence, values of the blood flow in arbi-
trary units were comparable for one animal and one element from experi-
ment to experiment .
k. Centrifugal acceleration was produced in a head-pelvis direc-
tion in a centrifuge with a small arm and fixed number of revolutions.
Near the animal's head, acceleration approximated 5 units; the pelvis
was subjected to accelerations approximating 10 units. For the stand-
ard test, accelerations lasting 30 seconds at 3O minute intervals were
readily tolerated, even when repeated several times. However, when con-
tinued steadily for 2-3 minutes, it was lethal for most of the rabbits.
5. The first centrifugation for 30 seconds had, as a rule, little
effect on venous outflow. After repetition, a typical reaction developed
in the form of a decrease in blood flow at the moment of centrifugation.
Venous outflow increased considerably after centrifugation was halted.
Finally, a decrease in venous outflow persisted, returning to normal
only after 20- 30 minutes.
6. Repeated centrifugation gradually intensified the reaction,
especially in the first phase and aftereffect. These phenomena were
summational and quite pronounced in the poorly "conditioned" animals.
The phase of increased blood flow was very irregular, disappearing in
some animals after repeated exposures.
21U
7. The decrease in blood flow during centrifugation "becomes more
intensified from day to day, if animals, at the "beginning of the experi-
ment, are subjected to daily accelerations. After a one day's break,
the first phase of the reaction became weaker and disappeared completely
in the "well-conditioned" animals, giving way to a phase of increased
blood flow or zero reaction at the time of centrifugation.
8. Blood supply to the brain may become inadequate after head-
pelvis accelerations. Subsequent increase in venous outflow may stem
from this and reflect the intensification of total cerebral blood flow.
9. Cerebral blood flow reaction to acceleration is simply a pas-
sive, mechanical shifting of blood toward the centrifugal acceleration.
It has been found that a massive, mechanical shifting of blood at the
time of centrifugation may be partially compensated or, contrariwise,
may predominate over compensation, depending on the animal's condition
and the sequence in which the accelerations are produced.
10. In most cases, temperature of the brain surface at the point
where the temperature- sensitive element was placed changed, upon cen-
trifugation, in a very stereotypical fashion. The background temperature
curve at this time looked the same in most of the animals.
11. The suggested experimental technique may be used to investigate
the conditioning of animals to the effect of mechanical overloads on
cerebral blood circulation. The same model can be of value in studying
the effect of some other flight factors (e.g., radiation) on cerebral
blood supply.
PATHOGENESIS OF HEMODYNAMIC DISORDERS AFTER EXPOSURE TO A
SUPERSONIC AIR STREAM
A. F. Kovalenko, Ye. Ya. Kaplan, V. P. Boyarkin and A. M. Klochkov
Earlier studies have demonstrated that an air stream at a subsonic
speed with an exposure of 0.2-0. 3 second causes insignificant functional
changes in the organism. However, when the stream begins to exceed the
speed of sound, it acquires new physical characteristics (jumps in
compression) that undoubtedly have an adverse effect.
The pressure from an air stream of considerable intensity (R
J v mech
19,000 kg/m ) and brief exposure (0.2-0. 3 second) produces a sharp
215
impact. The purpose of this investigation was to determine the changes
brought about in the cardiovascular and nervous systems by exposure to
an air stream delivered at supersonic speed.
The first series of experiments dealt with the effect of an air
stream (Vi = 1600 km/hour) on dogs whose arterial pressure, rate of
blood flow, rate and rhythm of cardiac contractions, EKG, functioning
of the brainstem centers (respiratory and vasomotor), and peripheral
nerves of the sympathetic and parasympathetic nervous systems were
recorded in acute experiments. The excitability of neural elements
and rate of blood flow were determined after injection with such drugs
as lobeline, epinephrine, pilocarpine, and acetylcholine. A study was
also made of vascular reaction to stimulation of the pressoreceptors
of the carotid zone (pressor reflex to constriction of the common carotid
arteries on the right and left).
The second series of experiments was concerned with the effects of
the air stream on animals with electrodes implanted in various cortical
and subcortical regions. At the moment when the rate of the air stream
reached a given intensity, a special stand with an attached animal was
pushed into the stream for 0.2-0. 3 second.
In most cases, the stream first caused an increase, then a slow re-
turn to normal, in the cardiac rate. Meanwhile, the EKG exhibited an
increase in voltage of the "P" wave in the 3rd lead as compared with the
"P" wave in the 1st lead, apparently the result of a change in the heart's
position in the thoracic cavity. Decreased voltage of the "R" wave in
the 2nd and 3rd leads is a sign of lowered myocardial function. A
change in voltage and interval of the "T" wave in the 2nd and 3rd leads
apparently results from impaired excitability of the ventricles due to
the development of circulatory disturbances, hypoxia, and disrupted
metabolism in the myocardium.
Our data indicate marked changes in excitability and conduction of
the heart muscle after exposure to an air stream at supersonic speed.
When the required regimen was set up for an air stream with an in-
tensity of Vi = 1600 mm/hour, a loud noise (about 120 db) developed and
regularly increased both arterial pressure (by 10-15 percent) and the
rate of blood flow (by 15-20 percent). However, the immediate effect of
the stream was a marked lowering of arterial pressure (by 3O-35 percent)
and a slowing of the blood flow (by 2O-3O percent). After 3O-6O minutes,
hemodynamic disorders became more pronounced and, in some cases, pro-
duced symptoms similar to those of traumatic shock. In addition, there
was a change in neuroreflex regulation of vascular tone.
Under the influence of loud sound, the pressor reaction to constric-
tion of the common carotid arteries became more pronounced than at the
216
beginning. The air stream caused a 20- 30 percent decrease in the pressor
reaction below the original level. This may have been due either to
diminished sensitivity of the pressoreceptors in the vascular zone of
the carotid sinus or to diminished excitability of the central and pe-
ripheral nervous formations .
In this connection, we thought it necessary to check the functional
state of the respiratory and vasomotor centers and the excitability of
the sympathetic and parasympathetic nervous systems. Under the influence
of the noise made by the air stream, the excitability of the vasomotor
center increased, as shown by the stronger pressor reaction to lobeline
(by 10-18 percent) than at the beginning. After the direct effect of the
air stream wore off, the pressor reaction to lobeline decreased (by 25-
k0 percent) and, in some cases, was almost entirely absent. There was a
correlation between changes in the hemodynamic indexes and functional
state of the vasomotor center.
The excitability of the respiratory center underwent a similar
two-phase change. Loud sound increased its sensitivity; the air stream
decreased it.
The functional state of the sympathetic nervous system changed as
follows: sound stimulation (noise of the air stream) caused the pressor
reaction to epinephrine to increase (by 10-15 percent), whereas the ex-
citability of the sympathetic nerves diminished appreciably (by 15-20
percent) after the impact of the air stream. The decrease in excita-
bility was paralleled by the development of hypotension.
The functional state of the parasympathetic nerves following strong
sound stimulation and direct exposure to the air stream was little af-
fected, as shown by the virtually imperceptible change in the depressor
reaction to pilocarpine and acetylcholine.
Sound stimulation was accompanied by an intensification of bio-
electric activity in the cortical and subcortical brain areas . Marked
changes following exposure to the air stream (appearance of slow waves
and decrease of amplitude of the biopotentials) were indicative of the
development of cortical inhibition.
Bioelectric activity in the subcortical formations changed in two
ways: in some animals, there was an increase in the biopotentials and
accelerations of the rhythm; in others, there was a decrease in the
amplitude of the biopotentials and a shift toward the slow oscillations.
A comparison of electrophysiological changes in the cortical and sub-
cortical centers with the hemodynamic changes shows their interrela-
tionship. Intensification of bioelectric activity was accompanied by
elevation of arterial pressure and rate of blood flow. Arterial pres-
sure fell when the slow waves appeared, but rate of blood flow slowed.
\n '1
217
Cardiac activity, hemodynamics (arterial pressure, rate of blood
flow), and functioning of various nervous formations (cortex, subcortex,
vasomotor and respiratory centers, sympathetic and parasympathetic ner-
vous systems) vary with the degree of trauma inflicted by the air stream.
Whenever special protective measures were taken, the effect of the
stream was less. Changes in the above-mentioned systems were vague.
EFFECT OF HYPOTHERMIA ON OXYGEN DEFICIENCY AT HIGH ALTITUDES
Ye. A. Kovalenko, V. I. Korol'kov and Ye. A. II 'in
The literature on emergency rescues at high altitudes still con-
tains few references to drugs capable of increasing the organism's tol-
erance of certain extreme factors, notably acute hypoxia. Yet numerous
theoretical studies and clinical medical practice indicate that there
are quite a few ways of increasing resistance to various kinds of
hypoxia. One of them is the creation of artificial hypothermia (I. R.
Petrov, V. A. Negovskiy, Bigelow, P. A. Kupriyanov, A. N. Bakulev, V. I.
Burakovskiy, G. V. Gubler, and others). It has been widely demonstrated
that artificial hypothermia causes a sharp decrease in oxygen utilization
and an increased resistance to different forms of acute hypoxia. The
present study was undertaken to determine the effect of hypothermia on
tolerance of acute hypoxia at high altitudes.
Experiments were performed on dogs with platinum electrodes im-
planted in brain tissue, with continuous recording, by an automatic
integrating analyzer, of the EKG, pneumogram, electrocorticogram (EKoG),
and electrothalamogram (ETG).
The partial pressure of oxygen (p0 ? ) in the brain was continuously
recorded by the polarographic method in order to study the rate of
deoxygenation of brain tissues. The pO was read in relative units,
with the pO in brain tissues during the breathing of air by animals
on the ground taken as 100 percent . Of 37 experiments performed, 20
were a control series on intact animals and 17 were on animals sub-
jected to different degrees of hypothermia.
The animals were chilled in a special heat chamber. An hour before
exposure, they were injected intramuscularly with 50 mg/kg of sodium
amytal, 5 mg/kg of hexamethonium bromide, and 5 mg/kg of diphenhydramine
hydrochloride .
218
The investigations involved rapid elevation (explosive decompression)
of the dogs in a pressure chamber from an altitude of U000 m to 15,000 m
in 0-5 second and from 12, 000 m to 27,000 m in the same time. During
elevation to 12,000 m the animals breathed pure oxygen, but during rapid
decompression to 27,000 m the oxygen was turned off and the animals
breathed the surrounding air.
The main index of resistance to acute hypoxia was the time from the
moment the animal reached the prescribed altitude until respiratory
standstill and the so-called "survival time", i.e., the time the animal
could be kept at the altitude and its vital activities subsequently re-
stored under ground conditions .
In the control series with rapid elevation to 15,000 m, the animals
not subjected to hypothermia died in 17-25 seconds, with spasms occurring
in 23-25 seconds. Oxygen tension in brain tissues diminished rapidly,
amounting to 17 percent of the original level in the cortex and Hi--20
percent in the subcortical formations of the thalamohypothalamic region.
At these altitudes, an initial tachycardia averaging 226 beats per min-
ute gave way to a pronounced bradycardia of 5° beats per minute.
The EKG at the end of the altitude period, exhibited preterminal
shifts in the form of decreased P and R waves, shifting of the S-T in-
terval, and sharp increase in the T wave. The EKoG and ETG revealed
intensified bioelectric activity, a sharp increase in amplitude of the
oscillations with gradual predominance of the slow rhythms at a fre-
quency of k-6 cps, and, finally, complete suppression of bioelectric
activity.
Respiratory standstill at this altitude was noted in the control
animals k-9 to 90 seconds after reaching it. If they were kept there
for 2-3 minutes, respiration could not be restored after they were
brought to the ground and they died despite prolonged artificial respi-
ration and injection of drugs (epinephrine, lobeline).
In the next series of experiments with elevation to 15,000 m, it was
impossible to prolong the time to respiratory standstill more than 2
minutes in anesthetized animals cooled to a body temperature of 3O-32 .
Moreover, the "survival time" did not increase markedly. While the
animals were at the altitude, there was a sharp reduction of p0 p in
brain tissues- -to 26 percent in the cortex and kO percent in the sub-
cortex. Pulse decreased to li+1 beats per minute followed by bradycardia
of 80 beats per minute. In some experiments the respiratory rhythm was
impaired. No pronounced excitation or spasms occurred in this series
of experiments, as they did in the control.
219
The next series of experiments involved cooling the animals to 22-
2k° after injection with the same drugs. It was possible to prolong the
time they stayed at 15,000 m after which their vital activities could
be restored. Respiratory standstill at this altitude also occurred
somewhat later, after 2-5 minutes, with cardiac activity preserved 3-7
minutes but with marked EKG changes.
However, even in these cases, pO in brain tissues fell sharply,
constituting 18-3O percent in the cortex and 10-52 percent in the sub-
cortex and at approximately the same intervals of time as in the cases
without cooling. This, in our opinion, is proof that acute hypoxia can
occur when there is a pronounced drop in partial pressure of oxygen in
the lungs. In such cases, as our investigations showed, the oxygen
present is rapidly washed out of the tissues. The data on bioelectric
activity of the brain show that in hypothermia the amplitude of the
bioelectric oscillations derived was somewhat less than that in intact
and anesthetized animals. On the EKoG, the correlation between the
frequency components scarcely changed while the bioelectric activity
of the dominant rhythms on the ETG diminished: for the 2-k cps fre-
quency band--from h.3. 2 to 28.7 percent; for the 1-2 cps frequency band--
from 35.3 to l8.4 percent of the total value of the EMF.
During the first 30 seconds that the chilled animals were at 15,000
m, the EKoG showed an intensification of bioelectric activity of from
2k to 37.6 percent for the 1-2 cps frequency band, from 26.5 to 29. 1 per-
cent for the 2-k cps band, and from 10. 9 to 15-5 percent for the I4.-7 cps
band. The same pattern was observed on the ETG. For example, by the
30th second, the bioelectric activity of the 2-k cps frequencies rose
from 28.7 to 35.U percent, that of the 1-2 cps frequencies from l8.k to
27 percent. After a few minutes at the altitude, bioelectric activity
in the cortex and thalamic region was completely suppressed.
In the next series of experiments, intact animals were rapidly
elevated from 12,000 m to 2?, 000 m. After 10 seconds, p0„ in the cortex
dropped abruptly to l6 percent of the original level and after 40-50
seconds--to IO-I3 percent. Respiratory standstill usually set in after
15-U0 seconds. The entire complex of hypoxic disorders developed much
more rapidly. Also, at 27,000 m, along with extremely acute hypoxic
conditions, the animals developed altitude tissue emphysema, reflected
in marked swelling of the body and desquamation of skin.
Cooling the animals to a body temperature of 22-30° slightly
lengthened the time before respiratory standstill as compared with the
control animals, but by no more than l-l/2 to 2 minutes. However, keep-
ing the animals at these altitudes more than 2 minutes made it impossible
to restore vital activities after they "descended". The picture of EKG
220
changes, bioelectric activity of the brain, and pO decrease curve in
brain tissues was virtually the same as that at 15,000 ra, but it de-
veloped much more quickly. It is interesting to note that the altitude
tissue emphysema in the animals cooled to 22-23° persisted, but was less
distinct, a sign that the emphysematous bubble contained both the fumes of
tissue liquids and gases rapidly flowing from the tissues with these
sharp degrees of decompression, as shown in special experiments.
The following conclusions can be drawn from our investigation :
(1) Shallow hypothermia (3O-32 ) of animals quickly elevated to
high altitudes does not increase the time before respiratory standstill
and does not prolong "survival time" at these altitudes.
(2) Deeper hypothermia (22-23°) helps to increase the time before
respiratory standstill at an altitude of 15,000 km, but by no more than
5 minutes, and at 27,000 m, by no more than 2 minutes. "Survival time"
at 15 km with hypothermia of 22-23° i- s somewhat longer, 7-10 minutes,
but at 27 km, no more than 2-2-1/2 minutes longer.
The reason for the comparatively slight increase in time before
respiratory standstill and in "survival time" may have been the physical
factor of the sharp and rapid deoxygenation of tissues, brain tissues
in particular, as shown by the study of pO dynamics. In our opinion,
this is one of the more important characteristics of acute hypoxia at
high altitudes as compared with the various kinds that may occur under
ground conditions, when hypothermia is a very effective preventive
agent .
EFFECT ON BRAIN OXYGENATION OF BREATHING OXYGEN DURING
ACCELERATIONS
Ye. A. Kovalenko, V. L. Popkov and I. N. Chernyakov
Some investigators believe brain hypoxia is one of the effects of
prolonged accelerations (P. K. Isakov, D. Ye. Rozenblyum, I. M. Khazen,
A. A. Sergeyev, Armstrong, and others). This view is based both on indirect
evidence (Akesson, Bjursted, V. B. Malkin, V. V. Usachev, A. S. Barer)
and on a direct study of oxygen tension in brain tissues (A. Ye. Koval-
enko, V. L. Popkov, I. N. Chernyakov).
221
There is information also concerning the favorable effect of
breathing oxygen at ordinary atmospheric conditions and, of excess pres-
sure on tolerance of accelerations (V. I. Babushkin, E. V. Marukhanyan,
Chernyak, Watson).
In the light of the foregoing, we thought it would be of interest
to study the dynamics of tension in brain tissues after exposure to
accelerations under conditions involving the breathing of air and oxygen.
Experiments were performed on dogs with platinum electrodes chroni-
cally implanted in brain tissue. The partial pressure of oxygen (pO )
was determined by the polarographic method in relative values (as a
percentage of the original). At the same time the EKG, pneumogram,
and EEG were recorded. Accelerations of from 2 to 12 g were produced
by revolving the animals in a centrifuge for 1-3 minutes in longitudinal
and lateral directions. Nineteen dogs were rotated 23O times.
The first group of experiments studied the dynamics of pOp in brain
tissues after accelerations with the breathing of air. The degree and
nature of changes in the pO were found to be determined by the intensity,
direction, and duration of the accelerations, as well as individual
characteristics of the animals. After accelerations of from 2 to 6 g,
there was frequently at the beginning of the rotation a brief rise in
pO of 5 to 10 percent above the original level, which was followed by
a drop. No such rise was noted in anesthetized animals. Accelerations
of greater intensity invariably caused a drop in brain p0 2 , particularly
marked with head-pelvis accelerations, averaging with k-6 g (l minute
duration) 84-92 percent of the original level, with 10-12 g, 6O-7O per-
cent. Often a low pO level persisted even after rotation was halted.
2
In view of the resultant severe hemodynamic disorders, pelvis-head
accelerations were used only up to an intensity of 8 g. The pO level
with this direction of the accelerations fell only slightly, amounting
after k, 6, and 8 g to 90, 86, and dk percent, respectively.
Lateral accelerations (back-chest, chest-back) of 2-8 g lasting
1 minute did not appreciably reduce brain pOg. With 10 and 12 g, the
pO level fell to 87 and 80 percent, respectively. Prolonging the
exposure to 3 minutes resulted in a more pronounced drop in the pO .
With 8, 10, and 12 g, it dropped to 85.9, 77.6, and 60 percent,
minim 111 in
'ft
respectively. Moreover, in some experiments with 3 minutes' rotation,
the animals' general condition deteriorated sharply. The EKG showed
bradycardia, extrasystole, decrease in the P and R waves, and sharp
increase in the T wave. Respiration became less frequent and the in-
halation phase lengthened appreciably. On the EEG could be seen a
marked predominance of the slow rhythms (up to i|— 5 c Ps), increase in
the amplitude of these rhythms, and, at times, complete suppression of
the bioelectric activity of the brain. In some cases it was necessary
to resort to artificial respiration to prevent death.
An interesting fact, one with practical significance, emerged from
the experiments with lateral accelerations. When the animal's head was
placed 15-20 cm above the horizontal platform to which its trunk was
fastened, pO fell more sharply than when the head was secured at the
level of the trunk. The drop in pO in the first case was within ap-
proximately the same limits as with the head-pelvis accelerations.
A second group of experiments involved rotating the animals while
they breathed oxygen. Chest-back and back-chest accelerations of 1, 10,
and 12 g lasting up to 3 minutes caused a much smaller drop in brain pO
than when rotation was accompanied by breathing air. When air was
breathed, these accelerations decreased pO to 85.9, 77-6, and 60 per-
cent; when oxygen was breathed, the pO level was 107, 98, and 93 per-
cent, respectively. When breathing oxygen, the dogs were more resistant
to accelerations, EKG and pneumographic changes were less pronounced,
and the p02 level was higher than in the control rotations after head-
pelvis accelerations. Oxygen breathing at an excess intrapulmonary pres-
sure of about 3OO mm Hg with lateral accelerations produced an even more
pronounced positive effect, which was clearly manifested only with ac-
celerations of about 10 g.
Our investigation shows that prolonged accelerations invariably de-
crease brain oxygenation, especially when applied in a head-pelvis
direction. This suggests that oxygen deficiency of the brain is impor-
tant in the pathology caused by accelerations. Further evidence is
provided by the fact that breathing oxygen helps to keep pO with accel-
erations of up to 10 g on a level close to the original and greatly in-
creases the tolerance of accelerations. In addition, a relatively mod-
erate drop in brain pO after accelerations that cause severe impairment
and incomplete correction of this impairment when the animals are rotated
223
while breathing oxygen, when pO remains at a fairly high level, implies
that other factors too are involved in the disorders caused by accel-
erations.
MORPHOLOGICAL LABYRINTHINE CHANGES IN DOGS EXPOSED TO RADIAL
ACCELERATIONS
R . Ye . Kogan and S . S . Makaryan
We were unable to find anything in the literature on the morpho-
logical changes that accelerations cause in the inner ear, except the
well-known studies of Wittmaak (1909) and Magnus (±92k) .
In 1961 we made a study of inner-ear morphology of dogs exposed to
single and repeated accelerations, with the intensity in the head region
ranging from 1 to 14.5 units for 1 to 20 minutes and at various angles
of trunk inclination from the rotation axis.
Examination of the temporal bones revealed hemorrhages in the mucosa
of the bulla, the meatus acusticus internus, and the perilymphatic
spaces of the inner ear. Hemorrhages were more common in the perilym-
phatic spaces of the cochlea than in those of the vestibular apparatus.
After comparing our results with those of Kimura and Perel'man
(1956, 1957) on obstruction of the inferior cochlear vein, we concluded
that hemorrhages in the perilymphatic spaces of the cochlea and ves-
tibular apparatus are clearly related to impairment of blood outflow
from the inner ear .
The present study, however, deals with morphological changes in the
labyrinth of 11 dogs exposed to accelerations of varying intensity, dura-
tion, and direction-- "head-pelvis " and "pelvis-head" while lying and
when the rotation axis passed through the cardiac region. The temporal
bones of the animals were removed as quickly as possible and immersed in
Held-Wittmaak fixing fluid within 15 minutes. A hole was drilled in
the bulla to permit better impregnation of the inner ear with the fix-
ing fluid.
Dogs 2k, 29, 30, and 31 (l series) were subjected once, in the
pelvic region, to accelerations of from 6 to 1h units lasting from 8
to 18 minutes. All but dog 31 died during the experiment. Dog 31 was
sacrificed with an electric current on the next day. Table 1 shows the
experimental conditions and the morphological inner-ear studies.
ro
ro
■p-
Table 1
No. of
dog
Acceleration in
the pelvic
region, units
Duration of
rotation in
minutes
Outcome
Hemorrhages
Left ear
Right ear
2k
30
29
31
6.0
H.O
12.5
12.0
18
Died
12
20
Died
Died
Sacrificed
next day
Slight in sacculus;
scala tympani of
main and middle
spirals
None
Slight in bulla
None
In fenestra ovalis
and fenestra ro-
tunda
In bulla cavity
Slight in scala
tympani of main
spiral
Extensive in peri-
lymphatic spaces of
cochlea
In middle ear (fe-
nestra ovalis, f.
rotunda, bulla)
In niche of fe-
nestra ovalis
225
It is evident from the data that hemorrhages in dogs 2k and 30,
were in the inner ear but in dogs 2k, 29, and 31 they were in the central
ear. Hemorrhages were more common in the right than in the left ears.
There were no hemorrhages in the left internal ear of dogs 29, 30, and
31. Dog 30 was of particular interest, for it had extensive hemorrhages
in the perilymphatic spaces of all the spirals of the cochlea in the
right ear, while its left ear was normal. Dog 2k was exceptional in that
it had extensive hemorrhages in the left inner ear, but only insignifi-
cant ones in the scala tympani of the main spiral in the right ear.
Hemorrhages were particularly massive in the middle ear- -in the bulla
and niche of the fenestra ovalis and fenestra rotunda.
Thus, accelerations of up to Ik units in the pelvic region produced
hemorrhages of varying severity in the inner and middle ears . In the
former, they were concentrated mainly in the perilymphatic spaces of
the cochlea, not in those of the vestibular apparatus.
The second series of experiments involved accelerations in which
the rotation axis passed through the cardiac region. Dogs 26 and 33
were exposed once in the head region to accelerations of 10 to 13-5 units
lasting 7 to 17 minutes; dog 32, to accelerations gradually increasing
in intensity from 7 to 17 units lasting a total of 57 minutes. These
animals died during the experiment. There were no hemorrhages in the
inner and middle ears of dogs 26, 32, and 33. Table 2 notes the ex-
perimental conditions and results of the morphological investigations.
In the third series of experiments, when the rotation axis passed
through the pelvic region, dogs 23, 25, 27, and 28 were exposed once in
the head region to accelerations of 2.3-5-7 units for 16-17 minutes.
Table 2
No of
Accelerations in
the head region,
in units
Duration of
rotation in
minutes
Outcome
Hemorrhages
dog
Left ear
Right ear
26
10
17
Died
None
None
33
13-5
7
Died
None
None
32
7
9
10
20
13
10
u
Ik
Died
None
None
ro
No. of
dog
Accelerations in
the head region,
in units
Duration of
rotation in
minutes
Table 3
Outcome
Hemorrhages
Left ear
Right ear
23
25
27
28
5-7
3-7
3-7
2-3
16
16
Ik
17
Died
Died
Died
Sacrificed
next day
None
None
In internal ear, in
niche of fenestra
ovalis and f. ro-
tunda
In scala tympani of
main spiral and
meatus acusticus
internus
Slight in sacculus
Slight in sacculus
Slight in scala
tympani of main
spiral
In meatus acusticus
internus, in mucosa
of bulla
In scala tympani of
main spiral
51?
227
All but dog 28 died during the experiment. Dog 28 was sacrificed with
an electric current on the next day (Table 3).
All dogs showed only very slight inner-ear hemorrhages. For ex-
ample, dogs 23 and 25 had only tiny hemorrhages in the sacculus of the
right ear, but none in the left ear. Dogs 27 and 28 had slight hemor-
rhages in the scala tympani of the main spiral and in the meatus
acusticus internus. Hemorrhages were noted only in the left middle ear
of dog 27.
The dogs of this series had less extensive hemorrhages in the
middle ear than did the animals of the first series, when the rotation
axis passed through the head region. It will be noted that the accel-
erations applied to these animals differed both in direction (opposite)
and in intensity (less).
Thus, study of labyrinthine sections of animals subjected to head-
pelvis and pelvis -head accelerations revealed hemorrhages in the middle
ear and in the perilymphatic spaces of the cochlea, apparently the re-
sult of venous stasis. No middle- or inner-ear hemorrhages were found
when the rotation axis passed through the cardiac region.
Findings
1. Accelerations of varying intensity and duration applied in head-
pelvis and pelvis -head directions produced hemorrhages in the middle and
inner ears of animals. Middle-ear hemorrhages showed mainly in the
perilymphatic spaces of the cochlea and in the sacculus.
2. No middle- or inner-ear hemorrhages were found in dogs that
died during an experiment in which the rotation axis passed through the
cardiac region.
SPEECH AUDIOMETRY AS A METHOD OF FUNCTIONAL DIAGNOSIS IN
FITNESS EXAMINATIONS OF FLIGHT PERSONNEL
V. M. Kozin
Functional diagnosis is now commonplace because of the large num-
ber of civil and military flight personnel and the complicated flight
conditions and piloting techniques posed by new, high-speed equipment.
Ill I II I II
228
Indeed, new selection and training techniques for spacecraft crews have
come into being.
Testing of hearing is an important part of the examination of flight
personnel in the Civil Air Fleet. Besides whisper acoumetry, timing-
fork investigation, and tonal audiometry, the examination includes
speech audiometry, which is of value not only in selecting persons suit-
able for work under noise and vibration conditions, but in instituting
preventive measures for persons already working under such conditions .
Clinical methods for early diagnosis of impaired hearing are very
time-consuming when large numbers of persons have to be examined. To
save time, hearing tests are sometimes made with only speech frequency
(500, 1000, and 2000 cps) tones, but these provide little information
on perception of low and high frequencies. Since the incipient stages
of impairment of the sound- conducting apparatus and cochlear dysfunction
cannot be detected without testing the perception of low and high tones,
this method is not very effective.
Our methods of testing hearing by using speech audiometry to deter-
mine the perception of groups of words with various frequency character-
istics can be used on a mass basis. Speech audiometry helps to reveal
incipient impairment of hearing, the degree of impairment being expressed
in decibels, and its frequency characteristics in relation to word group.
For speech audiometry we used a MAG-8 tape recorder from which a
written text was delivered through an attenuator with 5 db scale divi-
sions to telephones with rubber earpieces. We have been working of
late with a model U65 speech audiometer manufactured by "Krasnogvardeyets".
The calibration of both audiometers and the quality of the tape re-
cording were the same.
A small, specially equipped, dismountable sound-suppressing chamber
permitted testing not only in the clinic with a sound background of 36-
k0 db, but, when necessary, directly where personnel were working.
(The sound-suppressing capacity of the chamber for pure tones ranged
from 36 to 6k db, depending on their frequency characteristics.) The
examinee was alone in the chamber, and two-way communication was main-
tained by means of a microphone. One examination took 10-12 minutes.
The examinee was supplied speech in each ear separately with an
intensity equal to an intelligibility of 80 percent of the words sup-
plied. Lists of words containing all the Russian phonemes and lists
of monosyllabic words with words of medium and high frequencies and
with words of low frequencies were used in preparing texts for tape
recording. (The lists were prepared by G. I. Grinberg.) The table
consisted of three groups of words: general-frequency, high- and medium-
frequency, and low- frequency. These were successively recorded on a
229
single tape with sufficient intervals "between words to enable the ex-
aminee to repeat what he heard and with pauses between every 10 words.
Recordings were prepared in four versions. In general, one version
was sufficient for the investigation of each ear. Findings were re-
corded in decibels for each group of words separately and placed on a
tonal audiogram blank at the appropriate level in a straight line: data
on the general-frequency group of words in the 256-UOOO cps frequency
range; data on the medium- and high-frequency group of words in the
750-UOOO cps frequency range; and data on the low-frequency group of
words in the 100-256 cps frequency range. 0. V. Solovey found that the
values of audibility thresholds in speech hearing tests are 8-12 db
higher than the tonal threshold values in the range of 32O-U5OO osc/
sec. On the basis of these figures, we adopted for normal hearing the
following thresholds of intelligibility for 80 percent of the words:
for the general -frequency group of words --8 db above the tonal threshold;
for the high- and medium- frequency group of words- -1 3 db above the tonal
threshold; and for the low-frequency group of words--l8 db above the
tonal threshold.
Examinees perceived the general-frequency group of words with a
lower level of reproduction than the high- and low- frequency groups,
apparently because it included mostly polysyllabic words, which are
heard much more easily when transmitted at the level of threshold
audibility.
A comparison of the data obtained by whisper acoumetry and tonal
audiometry with our method of speech audiometry shows that the latter
confirms the findings of tonal audiometry and makes more precise the
findings of whisper acoumetry.
Any abnormalities in whisper acoumetry or in the tonal audiogram
and low perception of speech should alert the doctor to the need of
making a comprehensive ear examination.
Testing hearing with words is the most natural way of determining
this analyzer's functional capacity under flight conditions. Since
the proper hearing of words, especially in communication, is sometimes
crucial on the job, we are continuing to improve the use of speech
audiometry in physical examinations.
Speech audiometry is presently being employed with a noise back-
ground of 70-80 db and involves the use of "blank" noise. This is a
result of efforts to approximate actual flying conditions when examin-
ing personnel that uses a method for testing hearing against a back-
ground of noise made by various kinds of airplane motors recorded on
tape and played back in a sound- suppressing chamber at intensities
equaling those found in cockpits .
%
230
Another development is an audiometric method employing tables con-
taining the specialized vocabulary that can more accurately characterize
the functional capacity of the auditory analyzer under the examinees '
actual working conditions .
Our method of testing hearing through perception of groups of
words with different frequency characteristics has these uses :
(a) As an independent method in mass prophylactic examinations for
detection of the initial stages of hearing impairment.
(b) For dynamic observation of persons with impaired hearing and
for checking of the results of treatment thereof.
The method is recommended for both qualitative and quantitative
testing, especially in initial screening of personnel, because whisper
acoumetry does not always indicate hearing impairment.
EFFECT OF FLIGHT FACTORS ON THE ADJUSTING REFLEXES
G. L. Komendantov
It is well known that body balance is maintained by the adjusting
reflexes (Holz, V. M. Bekhterev, Magnus, V. I. Voyachek, Sherrington,
I. S. Beritov, L. A. Orbeli, and others). These oldest of reflexes,
which act against the force of gravity, are constantly functioning.
Operating simultaneously and closely coordinated with them are a variety
of other and younger motor reflexes, including the most complex of all,
the working movements (L. A. Orbeli, A. N. Krestovnikov, Sherrington).
Thus, any change in executing the adjusting reflexes inevitably
affects to some degree man's efficiency. This explains aviation medi-
cine's strong interest in the effect of various flight factors on these
reflexes . The few published reports on the problem relate to the ef-
fect of "elevation" in a pressure chamber and of breathing mixtures of
oxygen-deficient gases on post-rotation nystagmus of the eyes and head,
galvanic nystagmus of the eyes, labyrinth reflexes to the extremities
and to the position of the head, the straightening reflex from the
original position of lying on one's side, and the reflex of readiness
to jump (Gellhorn and Spiesman, 1935; I- Ya . Borshchevskiy and A. P.
Popov, 1936; Gellhorn and Storm, 1938; Sikorsky, 1938; Ya. A. Kizel ' -
shteyn, 1939; Stephen, 1939; A. P. Popov, I9I+O; A. A. Pukhal'skiy, I9UO;
Raverdino and Stieglich, 19^0; N. G. Savin, I9U6; G. L. Komendantov,
19^8, 1955; others. Most of the investigators either failed to find any
231
important reflexes or, if they did, noted their weakening at "altitudes"
of 5000-7000 in or their disappearance at 8000-10,000 m.
Our investigations dealt with the effect of the following factors
on individual adjusting reflexes and on body balance as a whole in
human beings and animals: "elevations" in a pressure chamber, breathing
of gas mixtures with low oxygen content, breathing of gas mixtures with
little oxygen but high carbon dioxide content, increased pressure in
the cavities of the gastrointestinal tract (simulation of altitude
meteorism), constriction of the common carotid artery (anemia), and
intense and prolonged accelerations .
1. We found that post-rotation nystagmus slows in rabbits "ele-
vated" in a pressure chamber to 5000 m or more (decrease in the total
number of nystagmic movements with unchanged duration of the reaction).
At 6OOO-65OO m in most cases and at 7000-9500 m, there is generally an
increase in the number of nystagmic movements with a simultaneous
lengthening of the reaction. The time the animals were kept at the
"altitudes" was 1 hour and 38 minutes.
Proprioceptive cervical and lumbar compensatory reflexes to the
eye muscles and muscle of the third eyelid were studied both while the
animals were in the pressure chamber at various "altitudes" (2000-
11,000 m) and when they were breathing gas mixtures containing 1.8-11
percent oxygen (17,000-50,000 m) . The exposure lasted from 1 to 58
minutes .
Meanwhile, we observed phase changes in the amplitude of the con-
tractions of the antagonistic eye muscles, muscles of the third eyelid,
and respiratory rate--indications that the induction relations among the
different parts of the brain (medulla, midbrain, etc.) had become in-
tensified. We also noted a transformation of the rhythm, loss of in-
dividual reflexes or groups of reflexes, slowing of the rate of contrac-
tion, appearance of "altitude" nystagmus, and other impairment of
reflexes .
The reflexes to the muscle of the third eyelid were less stable
than to the eye muscles, whereas the lumber reflexes were less stable
than the cervical.
2. The addition of carbon dioxide ( 1+ . 2-5 -8 percent) to gas mix-
tures deficient in oxygen (corresponding to altitudes of 9000 to 17,000
m) generally increased altitude resistance in rabbits, and the decrease
in tone of the eye muscles and muscle of the third eyelid was either not
too sharp or not observed at all .
3. Experiments involving simulation of altitude meteorism in
rabbits by raising the pressure in the gastrointestinal cavities and
esophagus 20-150 mm Hg revealed that in most cases this action caused
232
ocular caloric nystagmus to slow while the relations among the ampli-
tudes of the contractions of the antagonistic eye muscle changed. A
bilateral vagotomy did not prevent this effect, and subsequent transec-
tion of the posterior columns of the spinal cord excluded inhibition.
Inflating the stomach during respiration with gas mixtures deficient in
oxygen first stimulated, then inhibited it. Under these conditions,
too, the compensatory lumbar reflexes were less stable than the cervical.
h. Rendering the brain anemic by constricting one of the carotids
in rabbits for 3O-6O seconds caused a marked change only in post -caloric
nystagmus (effect on the induction processes).
5. Eabbits, cats, and dogs were exposed for O.k second to h seconds
to air streams at high speed (7OO-I395 km/hour). The adjusting reflexes
in rabbits were found impaired, beginning with speeds of 900-1000 km/hour
(l second exposure); in the cats and dogs, at 1100-1200 km/hour with the
same exposure. The labyrinth reflex to the position of the head and the
straightening reflexes from the original position of lying on one's back
and with the back dropping down proved least stable.
6. In rabbits, dogs, and monkeys exposed to intense (ll. 3-3^.7),
brief (O.O7-O.I5 second) accelerations in a head-pelvis direction with
a large gradient of increase (to kTk seconds), the adjusting reflexes
became impaired only when the tissues were injured: in the dogs, some-
what less than 25j in the rabbits, at the 28-3O level; and in the
monkeys, apparently with greater accelerations than 3O-35. Investiga-
tion of the effect of these accelerations on human beings showed the
intensities to be in the k to 22.7 range, duration--0.7 to 0.26 second,
and gradient of increase--to 3U5 seconds.
The adjusting reflexes cannot keep the head and upper part of the
trunk of man from large and sharp inclinations with free fixation,
starting with accelerations of 5.6 to 9, with a still small rate of
increase (70 to 100 seconds).
A suitable position, proper fastening of the body, and a well de-
signed armchair not only help to increase the tolerance of such strong
mechanical factors but preserve the necessary level of efficiency and
body balance (original position). Investigation of the balance function
during the aftereffect period (after 10 minutes) showed that it was com-
pletely restored by this time.
7. With exposure of human beings to prolonged accelerations in head-
pelvis and chest-back directions, a heavier load (more so with head-
pelvis accelerations) was borne by the adjusting reflexes because of the
need to maintain the balance of the body, which seemed to increase in
weight several times.
233
Intensification of the adjusting reflexes caused nervous system
excitability (irradiation of weak excitation) first to increase and then
decrease as a result of external inhibition, which affected the existing
conditioned-reflex activity (one of the mechanisms underlying the effect
of accelerations) accordingly.
8. Model experiments on rabbits revealed that, when cortical motor
acts interacted with the adjusting reflexes, the former suffered most,
to the point of complete disappearance when they interacted with multi-
directional reflexes (the ordinary combination of two adjusting reflexes
and their struggle for a common final path) .
SOME RESULTS OF A STUDY OF THE CARDIOVASCULAR SYSTEM IN
FLIERS ON DIFFERENT FLIGHTS
S . Ye . Komshalyuk
Heart and blood vessels constitute one of the most reactive systems
in the body. Even minor changes in the internal and external environ-
ments cause changes in pulse rate, vascular tone, blood pressure--
adaptive reactions designed to sustain the required level of physical
and mental activity. Therefore, the physiologists of work attach spe-
cial significance to cardiovascular condition in performing given tasks.
Since flying entails considerable nervous and emotional strain, study
of the cardiovascular system, especially during flight, is not only of
scientific but of practical value in devising measures to protect the
health of airmen.
N. M. Dobrotvorskiy (author of the book Letnyy trud (Flying),
1930), P. I. Yegorov. and others thought it very important to study the
cardiovascular system. However, for a long time, owing to the lack of
specialized miniature equipment that could be carried on board the air-
craft, this could be done only before and after flights.
The first investigations of the cardiovascular system of airmen
during flight were carried out on multiplace airplanes- -at first on
transport, then on military planes (G. Diringshofen, I938, 19^3; M - s -
White, 19^0, R. Ye. Kirsh, 19M*; A. V. Kaminskaya, 1953; others).
Development of miniature equipment made it possible to record
cardiac and respiratory rates and other indices during flight without
the presence of an investigator and without interrupting the airman's
activities on any kind of plane, including single-seaters (V. I. Babushkin,
niiiiiiiiiiiniiiiii
t:
23k
V. V. Usachev, A. S. Antoshchenko, V. A. Myazdrikov, N. P. Sergeyev,
and others) .
This investigation was aimed at studying the cardiovascular system
of men while carrying out long flights with a complex mission. We found
that these flights create a great deal of nervous, emotional, and physical
strain, one index of which is the state of the cardiovascular system.
For example, at critical times the cardiac rate of veteran pilots
ranges from lUO-160 a minute while that of trainees is 180 a minute.
The increase in cardiac rate is paralleled by an increase in respiratory
rate, amounting to kO-k^> and, in some cases, 50 respirations a minute.
Similar changes in cardiac and respiratory rates were observed in pilots
getting training on high -altitude, high-speed airplanes.
Thus, analysis of the literature and our own data shows that during
initial flights on new airplanes, regardless of type, or in the execution
of complex flight missions, cardiac rate may rise to lU0-l60 and even l80
a minute. In time, as the plane is mastered and familiarity with the
mission is gained, the nervous and emotional strain diminishes while
both the cardiac and respiratory rates decrease.
However, there are important differences with respect to the load
on the cardiovascular system of pilots of high-altitude and high-speed
airplanes and that of pilots completing long flights with a complex
mission. Whereas the former can relax after a short flight, the latter
must continue with many hours of flying after completing a mission in-
evitably accompanied by high nervous and emotional tension. Hence,
there are differences in cardiovascular condition after different kinds
of flight. After high -altitude, high-speed flights, the indexes of the
cardiovascular system are restored in 3O-5O minutes, but after flights
with a complex mission, restoration requires several hours. This can
be clearly seen on the EKG changes- -essentially an increase in the T
waves and a change in the R waves--indicative of impaired trophism of
the myocardium.
Blood cholesterol increases under high nervous and emotional ten-
sion. Frequent impairment of internal fluids (such as increase in blood
cholesterol) and cardiovascular strain may cause organic injury.
It will be noted that significant cardiovascular changes during
long flights with a complex mission occur only in those with major re-
sponsibilities. In those with minor obligations, emotional stress and
physical strain are less, while cardiac and respiratory rates are pro-
portionately less (to 120 and 30 per minute, respectively). The cardiac
rate does not change in crew members not involved in execution of the
mission.
235
Pulse increase before flight and decrease following flight are evi-
dence of the important part played by nervous and emotional factors in
cardiovascular strain.
Findings
1. Cardiovascular changes in airmen during flight depend largely
on the complexity of the mission and on the degree of newness of the
flight .
2. The cardiovascular system experiences considerable strain during
complex flight missions and in the course of gaining familiarity with
new airplanes.
3. In connection with pilot familiarization with new planes or
execution of complex flight assignments, aviation physicians should
give both preflight and postflight physical examinations to study the
nature and time of restoration of physiological functions, with focus
on the cardiovascular system (using the EKG, measurement of blood pres-
sure, and other methods).
h. To decrease the effect of adverse flight factors, it is essen-
tial to increase tolerance by physical conditioning and efficient rou-
tines, taking into account the degree of changes in the body which
depend on the duties of the crewmen during flight.
HISTOMORPHOLOGICAL CHANGES IN DOG PANCREAS AFTER EXPOSURE
TO LATERAL ACCELERATIONS
Yu . N . Kopaye v
Morphological changes in the organs and tissues of an organism
subjected to intense accelerations are of great concern to space medi-
cine. The purpose of this investigation was to study the effect of
single lateral accelerations on the histomorphology of the pancreas in
dogs .
There are just a few published reports on morphological visceral
changes in animals exposed to intense accelerations and virtually none
on the pancreatic effect of this factor. For example, Hell and Gran-
more (1953) merely mention the fact that intense accelerations cause
considerable shift and deformation in animal viscera and also bring
about a redistribution of blood in the vascular bed. Beckman et al.
236
(1953) found that monkeys exposed to accelerations of 40 g develop in-
terstitial hemorrhages in some of the viscera (lungs, kidneys, liver,
etc . ) with formation of foci of degeneration and regeneration . More
recently, data were published on the effect of space flight factors
on experimental animals: V. G. Petrukhin (1962) observed hemodynamic
disorders such as hyperemia, perivascular edema, and tiny hemorrhages,
as well as degenerative changes in some of the viscera, including the
pancreas .
We performed two series of experiments involving 28 male dogs
weighing 10-15 kg. The first series studied the effect of 8 g accelera-
tions in a chest-back direction for 3 minutes; the second, the effect
of 12 accelerations in the same direction for 1 minute. Five intact
animals of the same sex and weight served as controls. The animals
were sacrificed with ether fumes 1 hour, 1, 3, 7, 15, 30, and 60 days
after exposure- -2 animals at each time period. Pancreatic fragments
obtained by sagittal dissection were fixed in 10 percent formalin,
Zenker's fixing fluid in A. A. Maksimov's modification, and Carnoy's
fixing fluid. Paraffin and celloidin sagittal sections 5 and 10t-i thick
were treated with a variety of histological and histochemical methods:
hematoxylin-eosin, azure II-eosin, Mallory's azocarmine, for RNA with
methyl green-pyronin, and for DNA by Feulgen's method.
Analysis of the material obtained in the first series showed marked
venous hyperemia in the pancreas 1 hour after exposure. The inter-
lobular veins were markedly dilated and their lumens filled with blood,
with leukocytes on some of the margins . Around the interlobular veins
in some parts of the organ were hemorrhages about 500-800|J. in diameter
caused by rupture of the vascular wall (hemorrhagia per rhexin). There
was pronounced spasm of the small interlobular arteries and arterioles
at this time. In the gland parenchyma proper, sinusoid capillaries of
the islets were considerably dilated and overflowing with blood, while
the capillary network of the exocrine glandular tissue retained its
usual appearance .
An hour after the experiment, venous hyperemia in the pancreas was
even more pronounced, but more significant changes appeared in its
arterial system. Parts of the interlobular arteries and arterioles
showed signs of plasmorrhagia accompanied by vacuolation and desquamation
of the endothelium, as well as fraying and partial destruction of ele-
ments of the muscular and outer coats of the blood vessels. Some parts
of the organ had fresh microscopic hemorrhages around these altered
vessels apparently caused by diapedesis (hemorrhagia per diapedesin).
In two cases, parietal leukocytic thrombi were found in the lumens of the
interlobular arteries .
By the end of the third day, the general picture of the gland's
arterial and venous bed was close to normal. However, as a result of the
237
previous changes in parts of the organ, the interlobular blood vessels
•were surrounded by fairly distinct hemorrhages, which were gradually
resorbed between the 7th and 15th days, accompanied by moderate leuco-
cytic and fibroblastic reactions.
Changes in the parenchyma proper were reflected in reversible
dystrophic and irreversible degenerative processes. Dystrophic changes- -
noted in glandular tissue soon after exposure (l hour - 1 day) --affected
extensive areas. These changes were manifested in a marked decrease in
the amount of .RNA in the homogeneous zone of the exocrine glandular
cells and in a significant reduction in the amount of zymogenic granules
in their apical parts . The secretory cells of the islets appeared empty
at this time, with almost no proenzyme granules. Moreover, a careful
cytological investigation of the early specimens (l hour - 1 day) showed
the relatively frequent phenomenon of ejection of the nucleolus from the
nucleus in the exocrine glandular cells. This process was accompanied
by partial chromatolysis of the nuclear substance and was particularly
distinct in specimens treated for DNA, a phenomenon that warrants more
detailed study. The above-mentioned dystrophic changes in the gland
parenchyma gradually became normalized 3-7 days after exposure, at which
time the tissue regained its usual appearance.
Degenerative changes in the parenchymatous elements of the pancreas
were local in character and affected comparatively small areas near the
hemorrhages. In these portions, the glandular terminal sections and
individual secretory cells died soon after exposure. Sometimes the foci
of degeneration embraced small lobules in which the glandular elements
gradually atrophied and degenerated. Comparatively weak leucocytic
and macrophagic reactions were noted in the areas where the parenchyma-
tous elements died. Seven to 15 days after exposure, abnormally large
development of the small efferent ducts and intercalary sections along
with mitotic division of the centroacinar cells were noted in some parts
of the gland parenchyma. These were apparently a form of compensatory-
restorative reaction. All the pancreatic changes that arose after
exposure to the accelerations were compensated by the 30th day after
the experiment .
The second series of experiments involving exposure of animals to
12 lateral accelerations for 1 minute showed the same histomorphological
changes- -but not quite so pronounced- -as in the first series.
Thus, study of the pancreas of our experimental dogs shows that the
main changes that followed single lateral accelerations of 8 and 12 g
were the disorders caused by the impairment of blood circulation. In
addition, definite degenerative-dystrophic changes took place early in
the parenchyma of the organ. These subsequently gave way to phenomena
of a compensatory-restorative nature. The various changes that arose
in the pancreas after the accelerations were all adequately compensated
within 30 days of exposure.
238
THE LATENT FORM OF MOTION SICKNESS
V. I. Kopanev
It is well known that in traveling on water, in the air, or on
land, varying degrees of vertical and angular accelerations may cause
motion sickness in persons with low statokinetic tolerance. According
to some investigators, people differ in susceptibility to swaying motion
and type of vehicle. Hill (1936), M. Krivoshein and A. Sandler (1937),
and R. A. Okunev found that motion sickness affects more than 90 per-
cent of those traveling on boats, about 11 percent of those on propeller-
driven airplanes, and I-3 percent of those on jet planes (A. V. Chapek,
L. S. Isaakyan, et al., 1959)-
Classifications of motion sickness depend on type of transport,
main clinical symptom, etc. With respect to severity of sickness, a
distinction is now made between: (a) the manifest form characterized by
vomiting and other autonomic reactions, and (b) the latent form with
only slight deterioration in the sense of well-being and moderate impair-
ment of efficiency (Maitland, 1931J G. Shubert, 1937; Hemingway and
Green, 19^-5 1 V. I. Kopanev, I96I; others). The latent form is more com-
mon and generally occurs in the initial stage of each case of the mani-
fest form, although it is also found independently.
Our investigation, using essentially healthy males 19 to 36 years
of age, sought to determine the functional state of the visual analyzer
in the latent form of motion sickness. We used the method of "adequa-
tometry" (P. 0. Makarov, 1952, i960) to determine the excitability of
the visual analyzer from three thresholds (adequate optical rheobase,
adequate optical chronaxie, adequate optical topaxie) and its lability
from the critical interval of discreteness. Visual acuity was measured
on a Belostotskiy-Gofman apparatus. Swaying movements- -produced at the
rate of 16-17 per minute --lasted 30 minutes and were terminated when
subjects complained of slight nausea, sensation of heat flushes in the
head, etc. Accelerations did not exceed an intensity of 0.15 g. This
minimal acceleration and the individual approach to the duration of
the swaying produced only the latent form of motion sickness with no
autonomic changes. Blood pressure, pulse, and respiration were peri-
odically checked during the experiment.
Control experiments were run in order to determine the effect on
the visual analyzer of a darkened chamber with no swaying movements for
the period of time corresponding to the duration of the experiment (2
hours and k0 minutes). Indexes of excitability and lability of the
analyzer were found to be relatively steady, 3O-5O minutes after the
light was turned off.
239
Since swaying movements were not started until the subjects spent
at least 50 minutes in darkness, any changes observed in the functional
state of the visual analyzer could be attributed to motion sickness .
Results of the experiments showed that the visual analyzer's ex-
citability thresholds rose while its lability decreased. For example,
the rheobase during the first 5 minutes of swaying increased by 52
percent (from I5.9 to 23.7 relative units). Though it subsequently
fell slowly, it remained above the original level until the end of the
experiment. Chronaxie reached a maximum after 15 minutes of swaying--
2I4- percent above the original level (from 35. 7 to U^.2 msec), remaining
high for 35 minutes. Topaxie gradually increased, reaching a maximum
after 15 minutes of swaying (52 percent above the original level, from
86 to I3I mm ) . When the swaying movements stopped, topaxie quickly
returned to normal. The critical interval of discreteness changed as
soon as the swaying movements were started, reaching a maximum after
25 minutes (18 percent above the original level, from 67.3 to 79-1
msec) and remaining at this level with a slow shortening of the inter-
val until 25-^5 minutes of the aftereffect period.
Visual acuity decreased in 12 persons, increased in 7 } an( i remained
unchanged in 7- Th e pulse increased by 5-20 beats; blood pressure, by
5-20 mm Hg. From the start of the swaying movements, the respiratory
rate generally matched their rhythm.
The functional changes of the visual analyzer were directly re-
lated to resistance to swaying movements. In 13 subjects resistant to
30 minutes of swaying, there was an increase in the indexes, but it
was less pronounced and it occurred some time after the start (10-15
minutes) rather than immediately.
In 7 subjects, chronaxie and the critical level of discreteness
did not lengthen, but shortened, during the first 10 minutes, indicating
increased excitability of the visual analyzer. In 13 persons with low
resistance to swaying movements (they complained and the duration of
the action was shortened), changes in excitability and lability of the
visual analyzer were more marked and set in as soon as the action was
started). Yet in these cases, too, the initial measurements of the
rheobase, chronaxie, topaxie, and critical interval of discreteness
frequently were below the original values. This occurred also when
investigating visual acuity: a decrease, as a rule, in those with little
tolerance of swaying movements; an increase in those with high toler-
ance.
These findings are particularly interesting because, although the
subjects generally thought their condition quite satisfactory and their
autonomic reactions were slight, an objective investigation showed a
2ltQ
decrease in the excitability and lability of the visual analyzer and in
visual acuity.
In some cases, excitability first increased, but later decreased,
a situation comparable to phases 1 and 2 of motion sickness (G. L.
Komendantov and V. I. Kopanev) . The first and very short phase is
marked by excitation irradiating from the neural structures responsible
for spatial orientation, chiefly from the vestibular analyzer, to the
adjacent CNS regions, including the visual analyzer. With intensifi-
cation of excitation, negative induction gives rise to inhibition of
these regions (phase 2), resulting in decreased excitability and lability
of the visual analyzer.
The results of our study of the latent form of motion sickness
point up the need of carefully observing persons whose work exposes
them to slight angular and linear accelerations (fliers, drivers, sea-
men, etc.) regardless of whether or not they have any complaints.
Latent forms of impaired compensation are probably produced also
by other unfavorable environmental factors such as oxygen deficiency,
noise, and vibration.
Findings
1. Most subjects with the latent form of motion sickness exhibited
a decrease in excitability and lability of the visual analyzer and
slight changes in blood pressure and the cardiac rate.
2. A definite relationship was detected between these changes and
degree of statokinetic tolerance.
TRAINING MAN FOR SPACE FLIGHT
A. A. Koreshkov
The efficiency and endurance displayed by the astronauts were the
result of scientific selection and training methods. These methods rec-
ognized space flight factors regarded a priori as psychological and
physiological stressors (intense accelerations, dynamic weightlessness,
novelty, natural danger, loneliness, isolation, confinement in a small
space, sensory inadequacy, artificial day and night). Analysis of these
factors showed that the astronaut must have good health, particularly a
241
sturdy cardiovascular system, good physical development, adequate mental
and physical fitness, and high emotional stability characterized "by a
sthenic reaction to danger. Other qualities of importance include ves-
tibular stability and favorable experience with weightlessness and
maximum tolerance of noise, loneliness, isolation, confinement, and
sensory inadequacy.
This report examines cardiovascular reactions during parachute
training, exposure to vibrations, and prolonged confinement and isola-
tion. It reports also on the ability of a group of experimenters to
work harmoniously together under these conditions .
The parachute training plan included mastering the techniques of
jumping clear of the plane, controlling the body during the period of
free fall until the parachute opened, calculating the time until the
parachute opened, controlling the parachute during descent, and landing
on land or water with ordinary and special equipment (diving suit).
The program called for increasingly difficult jumps: (l) in the daytime
in good weather, (2) in the daytime in foul weather, (3) at twilight,
(4) at night under a starry sky, and (5) at night in foul weather. Dur-
ing the parachute training period, a cardiovascular check was made 1-2
hours before a jump, just before landing in an airplane, and then 45-60
minutes after the assignment was completed. One to 2 hours before a
jump, the EKG was recorded, arterial pressure measured, pulse taken
and its nature recorded (filling, tension, synchronism). The pulse
rate and its characteristics were recorded before landing in a plane.
The physical examination after a jump was the same as that given 1-2
hours before landing in a plane. The table presents averaged figures
obtained in a cardiovascular examination of Yu. A. Gagarin before and
after jumps.
Pulse Rate Before and After Parachute Jumps
(Mean Values)
Original
value
Before landing in an
airplane
After landing
1st day of
jumps
2nd day of
jumps
1 minute
3-7 minutes
1-1/2 to 2 hours
77
85
96
167
124
81
As these figures make evident, Gagarin showed high cardiovascular
tolerance of the physical and emotional stress in parachute jumps.
Pulse rate and EKG recordings for the other astronauts revealed the high
degree of stability they all possessed.
'T5
2U2
Tolerance of solitude, isolation, confinement and, as a result,
sensory inadequacy was determined by recording reactions during a pro-
longed stay in a sound- suppressing chamber. EKGs were recorded and
pulse was taken several times a day. On the last day the men spent in
the chamber, the pulse was somewhat faster than on the first day. Pulse
rate dynamics throughout the chamber interval provide evidence that the
figures are not accidental. EKGs showed normal myocardial function.
Investigation showed rapid adaptation to the effect of vibrations on
vital functions and, after overcoming transient and indistinct symptoms
of sinus arrhythmia, complete tolerance.
Of great practical and theoretical interest to space medicine is
the ability of a group of people to adjust to each other and work har-
moniously under conditions of prolonged confinement. According to lead-
ing foreign experts, who have organized small groups of people to stay
together under similar conditions (through the winter), this is a vir-
tually insoluble problem- -a view based on the neo-Freudianism that is
currently fashionable abroad, especially in America.
Participating in our study were several experimenters who remained,
for an extended period, in a specially equipped soundproof chamber,
their work and rest followed a designated program. Their physiological
and psychological reactions showed that a group of Soviet citizens,
fully aware of the importance of the mission can remain together for a
long time isolated and confined to a small place without any deteriora-
tion in relations . They also showed that these relations are deter-
mined primarily by the moral qualities of the individuals concerned and
by the extent to which they can coordinate their mental activity.
With respect to physiological functions, especially the cardio-
vascular, no marked abnormalities were noted in any of the members of
the group .
WEIGHTLESSNESS FROM THE STANDPOINT OF TERRESTRIAL PHYSIOLOGY
P . A . Korzhuyev
The problems deriving from the conquest of space require solution
largely under terrestrial conditions. A very important and too little
understood problem is weightlessness. Its uniqueness is primarily that
it is still impossible to produce prolonged weightless conditions on
earth for study of their effects on animal and human organisms.
21+3
Despite our ignorance of the subject, there is a tendency to re-
gard prolonged weightlessness as harmless, chiefly because astronauts
Nikolayev and Popovich were exposed to it for several days with no ad-
verse effects . It would seem preferable, in our opinion, to attempt an
objective evaluation of this factor before drawing any final conclusions.
The solution, we believe, must be based on the assumption that one of the
fundamental laws of biology--the unity of organism and environment- -is
just as valid for outer space as it is for our planet, and to plan our
research on this basis . One aspect of the research will be discussed
in this report.
Enough information is now available about the biology of present-
day animals, the vertebrates in particular, to permit some judgments
about the probable effects of prolonged weightlessness. However, de-
spite our knowledge, one factor still remains insufficiently under-
stood- -gravity . This has not been taken into account in describing
either the animals themselves or their habitat. The fact that the
force of gravity is not the same under terrestrial and aquatic condi-
tions will help to elucidate its role both in the life of organisms
and in the evolution of present-day animals.
Available experimental data on the morphology and physiology of
certain vertebrates help to understand the influence exerted by gravity.
Specifically, the quantitative data on blood, hemoglobin, and charac-
teristics of the centers of hematopoiesis in some fish, birds, and
mammals indicate that, philogenetically, a sharp boundary line can be
drawn between aquatic and terrestrial vertebrates.
We have shown that in the course of evolution .toward a terres-
trial mode of life, the amount of blood and hemoglobin increased in
the first creatures to settle on dry land. Quantitative analysis of the
centers of hemoglobin and erythrocyte synthesis in the vertebrates studied
revealed that the increase was due chiefly to the appearance of a new
center of hemoglobin synthesis--bone marrow, which arose as a result of
intensified gravitational force. Overcoming this force was indispensable
to terrestrial creatures in obtaining food, and gaining protection from
enemies and unfavorable conditions.
In the light of the foregoing, it is to be expected that the better
adapted a vertebrate is to terrestrial conditions and the higher it is
on the phylogenetic ladder, the better developed will be the centers of
hemoglobin synthesis in the form of bone marrow. Existing evidence,
although still very meager, supports this view. The amount of bone
marrow in such a fleet animal as the mature reindeer is 7 percent of
body weight, and as much as 13 percent in a newborn reindeer. On the
other hand, it scarcely exceeds 1 percent in a sluggish animal like
the guinea pig, which may spend its entire life in a cage. A quantita-
tive comparison of the hematopoietic centers in fish and in terrestrial
2kh
animals shows that the rate of hemoglobin synthesis is tens and hundreds
of times greater in the latter.
These data tend to support the view that terrestrial vertebrate
evolution is essentially development of adaptations to the force of
gravity, a process entailing intensified expenditures of energy by
liberation of large amounts of oxygen. The uptake of the necessary
amount of oxygen was determined by the presence of hemoglobin, the syn-
thesis of which had to increase sharply.
Increased oxygen need could not in itself have been sufficient to
change the centers of hemoglobin synthesis, for, if so, simple intensi-
fication of the ancient centers of hemoglobin synthesis would have been
enough. The main reason for the change in the centers was apparently
the unequal load on different parts of the organism under terrestrial
conditions. If this assumption is correct, more active animals should
have greater amounts of bone marrow, let alone a heavier skeleton. Ac-
cordingly, the higher vertebrates, which are not only better organized
but more active, should have the heaviest skeleton. It is worth noting
that an increase in skeletal weight is determined by the weight of the
bone-marrow fraction since it sometimes constitutes about ij-5 percent of
the entire skeleton.
Thus, if the vigor of the centers of hemoglobin synthesis is deter-
mined by gravity, removal of gravity should result in a depression of
bone marrow, in a reduction of its activity. Applied to space flight
conditions, this would mean that after prolonged exposure to weightless-
ness, when the force of gravity on the organism is completely excluded,
bone -marrow activity would no longer be stimulated by the ordinary
terrestrial factors and depression would set in, followed by degenera-
tion of these structures.
We believe, therefore, that an essential requirement for extended
space flights, which are not as remote as they seemed a few years ago,
is determination of the effects of weightlessness and setting up opti-
mum conditions to prevent any injurious consequences. Current attempts
merely to discover the possible effects of essentially brief periods of
weightlessness on various objects can be ignored, for they add little to
our understanding.
2k5
DEVELOPMENT AND PRESERVATION OF A HIGH LEVEL OF MOTOR FUNCTION
AS A PROBLEM IN THE PREPARATION AND EXECUTION OF EXTENDED
SPACE FLIGHTS
A. V. Korobkov
Man evolved in a state of constant interaction both with natural
factors (air, temperature, natural radiation, gravitational field,
time, space, electromagnetic field, etc.) and with social factors in-
volving a variety of relationships during work, at home, etc. The
motor function played an important and specific role in this process .
Terrestrial conditions do not exist during space flight, during
which various mental, autonomic, and motor processes — controlled by
reflex and humoral mechanisms through a vast flow of information gen-
erated by stimulation of different analyzers --change or become extin-
guished. Weightlessness, hypodynamia, and isolation largely reduce the
flow of information produced by human motor activity.
The motor function in man, which represents a form of "protest"
against the gravitational forces, is, so to speak, one of the important
biological links between his various autonomic and mental functions.
To illustrate this, we investigated the value of physical training in
maintaining mental, motor, and autonomic stability and in preserving
the relative constancy of the organism's internal environment under
varying states and environmental conditions. At the same time we
studied man's equilibrium processes and actions in the surrounding
environment (social and natural) with exposure to gravitational forces,
time, space, altered gas medium, etc.
Our study of the changes that take place in different organs and
systems under conditions of hypodynamia and isolation showed that mental
as well as motor and autonomic functions are affected. The marked de-
crease in resistance to radiation after hypodynamia indicates that the
lack of physical movements and ensuing reflex and humoral stimulation
exert a profound and unfavorable effect on intimate processes in various
organs and tissues. However, the performance of physical exercise in
the course of hypodynamia restores the quality of these functions.
Further research on resistance to radiation and tuberculosis con-
firmed our view of the great importance of hypoxemia and hypoxia created
by sufficiently intense and prolonged physical exercise in increasing
resistance. This was clearly demonstrated in animals, experimentally
infected with tuberculosis, whose death was directly linked to decreased
endurance of static exertions which are accompanied by a large oxygen
debt and high resistance to hypoxemia. Speed and strength were less
affected, although decrease in resistance to ionizing radiation, which
2h6
we frequently observed, was also accompanied by decrease in strength,
speed, and endurance. On the other hand, preliminary physical training
increased resistance.
We concluded from the foregoing that stability of the internal
environment is related to a high level of motor activity and develop-
ment of a definite interdependence of the qualitative characteristics
of this activity. The influence of this "interdependence" seems to be
due to the activation and interaction of certain trophic and autonomic
reactions concerned with speed, endurance, and dexterity.
Presenting animals with optimal electrical stimuli as equivalents
of physical exercise results in intensified emotional reactions and
resistance due to the trophic influences of CNS and hormonal factors .
Since the various organs and systems interact, each function affects
the whole organism, and, therefore, stability and environmental balance
depend on integral interaction in the entire range of activity.
Treadmill experiments (A. V. Korobkov, i960, I96I, 1962; V. A.
Shkurododa, I96I, 1962) on humans with various degrees of physical con-
ditioning revealed a complex picture of interaction and mutual compen-
sation chiefly in the motor and autonomic functions ( "spectrum" of re-
actions) as well as in certain physiological aspects of motor and
autonomic functions. A principal discovery (reflecting the integrated
aspect of resistance) was that persons in good physical condition were
resistant both to individual functions and to the entire "spectrum" of
reactions, whereas untrained persons showed much less definiteness and
inner unsteadiness. Physical conditioning, we found, plays a major
role in the development and resistance of several psychic functions
and mental efficiency.
Our data (Korobkov et al . , 1962, I963) showed that conditioning the
processes of environmental balance and motor stability contributes to the
formative influence of the ambient factors themselves in the develop-
ment of motor and autonomic functions. Conditions in a gravitational
field form the topography of the strength, speed, endurance, and struc-
ture of different neuromuscular structures, tone of various muscle
groups, direction of the trophic influences of the CNS, and vascular
tone regulation.
It is a reasonable generalization that existence in time and space
is responsible for the development of mental as well as motor skills and
qualities, and conditioning helps to perfect their topography.
The effect of physical conditioning and environmental factors
stems from activation of various analyzers, particularly, the motor ana-
lyzer. Vigorous motor activity, static exertions, and increased muscular
2k7
tone, by stimulating a vast flow of sensory information that contributes
through the reflex mechanisms to stability of higher nervous activity,
have both a trigger and a trophic effect on various tissues, activate
endocrine gland function, and favorably influence the resistance of the
vestibular apparatus to accelerations. Preliminary physical training
and physical exercise during flight can help shape man to achieve a
balance between his internal and external environments .
In the light of the foregoing, we regard a program of motor activ-
ity, in which physical exercise plays an important part, as a means of
preserving the terrestrial "spectrum" of information, which is required
to ensure the optimal condition of the biological environment of the
organism and, as a result, enhance psychic activity and mental effi-
ciency.
EFFECT OF LATERAL ACCELERATIONS ON DOG LUNG HISTOLOGY
Yu. N. Korolev
The tolerance of lateral accelerations by the respiratory organs
is determined by certain pathophysiological changes- -dyspnea, retro-
sternal pain, hemoptysis, and deoxygenation of arterial blood (A. R.
Kotovskaya, S. I. Lobashkov, S. F. Simpura, P. M. Suvorov, and G. F.
Kblebnikov, 1962; Muller, 1961). The direct causes of circulatory and
respiratory dysfunction after lateral accelerations are changes in
pulmonary ventilation and redistribution of blood in the pulmonary blood
vessels (P. V. Vasil 'yev, A. D. Voskresenskiy, and 0. G. Gazehko, I963;
A. A. Kiselev, 1962) . Hemodynamic changes in the pulmonary circulation
after accelerations have been investigated roentgenologically (A. R.
Mansurov, 1956; Muller, I96I; Hershgold, i960) . The authors noted that
the pulmonary lobes from behind were less transparent than usual, a sign
of the blood flowing back to the posterior sections of the lungs (an
apparent "separation" between blood and air, which creates unfavorable
conditions for pulmonary ventilation).
A few investigators have observed structural changes in lung pa-
renchyma after various kinds of accelerations. Beckman et al. (1953)
exposed a female chimpanzee to a positive acceleration of UO g for 15
seconds; autopsy, an hour later, showed edema, hemorrhage, and local
atelectases in the lungs . Lung parenchyma were overflowing with venous
blood, with thrombi in the lumens of the small veins. V. G. Petrukhin
(1962), investigating the viscera of mice and guinea pigs carried on
space vehicles, observed pronounced hyperemia and perivascular edema in
the lungs 2-3 days after the flight.
2U8
However, these morphological findings do not provide conclusive
evidence of dynamic pulmonary changes. The purpose of this investiga-
tion was to study the structural changes in the lungs of dogs after a
single exposure to lateral accelerations in a back-chest direction.
Two series of experiments were performed on 28 male dogs weighing
10 to 15 kg. The first consisted of a single positive acceleration of
8 g for 3 minutes ; the second, a single positive acceleration of 12 g
for 1 minute. The animals were sacrificed 1 hour, 1, 3, 7, 15, 30,
and 60 days after the experiment with ether fumes. The material was
fixed in Zenker-formalin, 10 percent neutral formalin, and Camoy's
fixing fluid and treated by the following methods : hematoxylin-eosin,
azure II-eosin, Mallory, Van Gieson, Tentser-Unna; impregnation by
Karup's method. The lungs of 5 male dogs weighing 10-15 kg served as
the control.
Because of the similarity of changes noted in the first and sec-
ond series, they are herewith described together. Gross inspection
after 1 hour and after 1 day revealed hemorrhages 0.2-0.2 cm to 2-3 cm
in size primarily located on the posterior surface of the lungs or in
the root zone. On the 3rd and 7"th days after the accelerations, ele-
vated grayish-red spots were noted on the pleural surface with dark-red
zones of atelectasis between them. At this time some of the animals had
confluent foci of pneumonia occupying a large part of the lobe . Much
later (after 30 and 60 days) some of the animals showed sclerotic patches
of different sizes under the altered pleura.
Microscopic investigation after 1 hour, and again after 1 day, re-
vealed hyperemia, thickening of the interalveolar septa, and activation
of their septal elements. The lumens of the alveoli contained cells of
desquamative epithelium. The blood vessels were dilated and filled with
blood while the surrounding connective tissue was loosened by a transu-
date. Some of the small blood vessels showed signs of stasis, with a
slight infiltration of small cells. Hemorrhages and atelectases of dif-
ferent sizes could also be seen. The former originated both per diapede-
sin and as a result of rupture of blood vessels (small veins and arte-
rioles). Blood not only filled the alveoli but was present in the
interalveolar septa, alveolar ducts and bronchioles. Near the hemor-
rhages were lacerations of the elastic fibers of the interalveolar
septa. Argyrophile fibers were coarse, swollen, and twisted. Also,
there was a focal decrease in the impregnation properties of the ar-
gyrophile fibers .
Patches of bronchopneumonia and confluent bronchopneumonia were
noted 3 and 7 days after the experiment . There was a proliferation of
cellular elements and leucocyte infiltration in the thickened alveolar
septa. Some of the alveoli had a serous exudate; others contained
cells of alveolar epithelium and leucocytes. Bronchitis, peribronchitis,
2k9
and bronchiolitis were pronounced. The alveoli surrounding the pneu-
monic foci had thickened interalveolar septa and a serous fluid with a
few alveolar cells .
In cases of pneumonia of the serous-desquamative type, the alveolar
cavities contained numerous cells of alveolar epithelium with many-
rounded cells and vacuolated cytoplasm among them. Argyrophile fibers
in these areas were difficult to impregnate.
Investigation of the lungs after 15, 30, and 60 days showed focal
sclerosis in some areas against a general background of normal lung
tissue. The connective tissue was proliferating along the interalveolar
septa and sometimes completely filled the alveolar cavities; it was
also proliferating under the pleura and between the lobules.
Results of our investigation show the following early (l hour, 1
day) characteristic changes in lung histology: hyperemia, edema of lung
tissue, and hemorrhages, all indicative of impaired hemodynamics in
the pulmonary circulation under the influence of accelerations. Later
(3 and 7 days), inflammatory phenomena developed in lung tissue. Still
later (15 and 60 days), there was focal sclerosis of lung parenchyma due
to organization of the previously existing hemorrhages or to pneumonia.
The above-described changes did not affect the respiratory function
significantly. Compensation was quite pronounced.
EFFECT OF LATERAL ACCELERATIONS ON DOG KIDNEY HISTOLOGY
V. V. Korolev
The few morphological studies of the effects of accelerations on
the kidneys and on the excretory system as a whole dealt mainly with low
intensity exposures. Senelar et al . (1959)> subjecting dogs to accel-
erations of 2.5 g in the head-pelvis direction, found on autopsy marked
hyperemia of the glomeruli, dilatation of the peritubular capillaries,
and ruptures of the venous walls. The brush borders disappeared in the
renal tubules while granular casts were sometimes found in the lumens
of the collecting tubules .
In another study, Senelar and Luber (i960) subjected dog kidneys
to positive accelerations of 2-5 g lasting from 10 to 60 hours and found
capillary and venous hyperemia of renal cortical and medullary substance,
numerous interstitial hemorrhages, desquamation of the epithelium of
the renal tubules, and the formation of casts. Dogs dissected 3 months
250
after the experiment had interstitial and glomerular sclerosis and
marked degenerative changes in the tubules . The authors believe that
summation of the effects of centrifugation caused progressive impair-
ment of neurovascular tone and persistent increase in passive blood
filling, which produced sclerosis and degenerative changes in the
tubules of the nephrons. However, these conclusions were drawn from
an experiment involving only a small number of animals.
Beckman et al. (1953) subjected anthropoid apes to positive ac-
celerations of U0 g for 15 seconds, and at autopsy, an hour after the
action, they noted enlargement of the kidneys, overflowing of the
glomeruli with blood, and dilatation of the tubules. V. G. Petrukhin
(1962), who studied the viscera of mice 2-3 days after they were car-
ried on space vehicles, found impaired kidney circulation in the form
of hyperemia, perivascular edema, and small hemorrhages.
The present investigation studied morphological changes in the
kidneys of dogs subjected to single lateral accelerations. The ex-
periments were performed on 28 male dogs weighing 10-15 kg subjected
once to accelerations of 8 g for 3 minutes or 12 g for 1 minute. The
animals were sacrificed with ether fumes 1 hour, 3, 7 j 30, and 60 days
later- -2 animals at each period. The kidneys of 5 animals served as
the control. The material was fixed in 10 percent neutral formalin,
Carnoy's fixing fluid, and Zenker -formal in in Maksimov's modification,
and then embedded in paraffin. Sections 5u thick were stained with
azure II-eosin, hematoxylin-eosin, and by Mallory's method. Histo-
chemical reactions to RNA were determined by Brachet's method, as were
reactions to mucopolysaccharides (PAS-reaction) . Sections 10-15l-i thick,
prepared in a freezing microtome, were stained for lipids with Sudan
III.
The morphological changes in the kidneys, as noted in the series of
experiments, included injuries to the vascular system and degenerative
changes in the renal tubules.
An hour after the accelerations, microscopic investigation revealed
marked hyperemia of the cortical and medullary substance in both kidneys.
There was considerable, frequently uneven dilatation of the capillaries
of the vascular glomerulus and transudation of plasma into the cavity of
the glomerular capsule as well as diapedesis and limited hemorrhages
around the renal corpuscle near its vascular pole. The peritubular
capillaries and venules were also dilated and were compressing the
tubules of the nephrons . The brush border of the proximal portions of
the nephrons had peeled off in places and their lumens were dilated
and filled with fine pyroninophil granules which, according to Oliver
(19^8), are plasmatic proteins subjected to calcium reabsorption. These
phenomena were indicative of increased glomerular permeability. Cells
with pycnotic nuclei were found in the walls of the straight tubules of
251
the nephrons. The walls of the distal tubules and ascending portions of
the loop of Henle contained degenerating cells with an amorphous sedi-
ment in the lumens .
The hyperemia of the renal cortical and medullary substance per-
sisted for the first three days. The capillaries of the vascular glom-
eruli, especially in the juxtamedullary zone/ were unevenly dilated and
filled with blood. At the same time we noted the collapse of the loops
of the glomerular capillaries, diapedesis, and transudation of blood
plasma into the cavity of the glomerular capsule. There were, in addi-
tion, some instances of lipid infiltration of the glomerular capillaries,
and the peritubular capillaries were dilated. The walls of the small
veins were ruptured, with hemorrhages around the small blood vessels
and leucocytic infiltration of the tunica adventitia and, in some cases,
lipid infiltration of the vascular walls. As for the tubules, the
changes were most distinct in the distal portions of the nephrons : the
protoplasm of some cells was vacuolated, the nuclei were hyperchromic
and pycnotic, and degenerated cells filled the dilated lumens of the
tubules .
Traces of capillary and venous hyperemia were still evident on the
7th day. Around the juxtamedullary glomeruli could be seen fresh cir-
cumscribed hemorrhages. The afferent arterioles of these glomeruli were
dilated and the endothelium of the capillaries contained lipid inclu-
sions. Delicate collagenous fibers appeared on the sites of the old
hemorrhages around the glomeruli. Degeneration comparable to that de-
scribed above was most pronounced in the ascending portions of the loop
of Henle and distal tubules of the juxtamedullary nephrons.
The venous and capillary hyperemia persisted for 15- 30 days. Fresh
hemorrhages appeared around the juxtamedullary nephrons, between the
tubules and cortical substance, and around the veins on the border be-
tween the renal cortical and medullary substance. Connective tissue
proliferated around the glomeruli and small blood vessels at the site
of the old hemorrhages. The proximal portions of the nephrons at this
time were similar in structure to those of the control animals, but the
walls of the ascending portions of the loop and distal tubules contained
degenerating epithelial cells that had peeled off in layers and filled
the lumens of the tubules.
By the 60th day, hemorrhages could no longer be found in the kidney
parenchyma: focal proliferation of connective tissue appeared at the site
of the old hemorrhages.
Thus, the morphological changes noted in our experiments were oc-
casioned primarily by the hemodynamic shifts that arose as a result of
the accelerations. Ames et al. (1951) have shown that positive accel-
erations of 2-3 g for 15 seconds increase venous pressure in the kidney
blood vessels about k-k.5 times (from 1-5 to 7-l8 mm Hg) while arterial
pressure falls 1.5-2 times. During the first few hours and days after
the experiments we noted venous hyperemia and focal hemorrhages around
the glomeruli and between the tubules, and increased permeability of
the walls of the capillaries of the vascular glomeruli, as indicated
by the erythrocytes found in the lumens of the tubules. The hemor-
rhages that appeared later (after 7 > 15> an( i 30 days) were apparently
caused by increased vascular permeability and decreased neurovascular
tone (Senelar and Luber, i960) resulting, perhaps, from the ether fumes
used to kill the animals. The above-mentioned vascular changes obviously
caused tissue anoxia in the kidneys and mechanical compression of the
tubules of the nephrons, which led to degenerative changes. It will be
noted that the distal portions of the nephrons, which are highly sensi-
tive to anoxia and other injuries (Smith, 195l)> were affected most of
all.
The morphological changes were more pronounced in the first series
of experiments than in the second, especially in the vascular system.
Hemorrhages into the cavity of the glomerular capsule and kidney paren-
chyma were more numerous and ruptures of the venous walls were seen more
frequently .
Beginning with the 7"th day, signs of organization of the old hemor-
rhages around the glomeruli and between the tubules of the nephrons
appeared and gradually increased. Degenerative impairment of the distal
portions of the nephrons remained a long time (about 3O days), but the
structures of the proximal portions were restored much sooner. Conse-
quently, the changes that arise in the vascular system and parenchyma
of the kidneys after accelerations are unstable and eventually become
adequately compensated .
PSYCHOLOGICAL AND PHYSIOLOGICAL CHARACTERISTICS OF THE WORK OF
AIRPLANE CREWS IN CONNECTION WITH IN-FLIGHT REFUELING
F. P. Kosmolinskiy
One of the most difficult aspects of flight training is to refuel
in the air on long flights. The danger of delicate maneuvering of the
plane causes considerable nervous and emotional strain in the crew, with
marked decrease in efficiency. Our I96O-I962 investigations (F. P.
Kosmolinskiy, S. Ye. Komshalyuk, N. A. Fedorov, I. M. Khazen, I. Ye.
Shramko, I. G. Dlusskaya, and others) showed that strain is manifested
primarily in autonomic changes. Veteran pilots manifested a cardiac
253
rate of IU5-I6O a minute; trainees, up to 180, thereby exceeding the
original values 2 to 2-l/2 times. Respiratory rate also increased
from 35-5O a minute, i.e., 2-l/2 to 3 times above the original values.
Long flights were followed by 5 percent weight loss (mainly
through dehydration) and a decrease in some physical indexes: strength
of the respiratory muscles, maximum muscular force, and muscular en-
durance (up to 50 percent), characteristic nervous arid mental changes,
and changes in the indexes used to judge attention (span and shifting
of attention, rate of visual perception). The latent period of sen-
sorimotor reactions lengthened as did the time of dark adaptation of
the visual analyzer. The thresholds of electric excitability of the
eye (phosphene) and of the critical frequency of coalescence of flicker-
ings were raised and the conditioned reflexes in response to given
muscular exertion were impaired. All these abnormalities were quickly
repaired, as a rule, but in a few instances persisted for some time
(about 2 days) .
With increasing skill, autonomic manifestations of nervous and
emotional strain and CNS functional changes as detected by physiologi-
cal and psychological methods, clearly improved.
Emotional excitement (accompanied by a sharp increase in cardiac
and respiratory rates) may, according to the literature, sometimes give
rise, as a result of hyperventilation, to hypocapnic, hypoglycemic,
and secondary hypoxic manifestations. These, in turn, influence the
cortical and, consequently, the mental processes.
Strong nervous and emotional stress may be expected to bring bio-
chemical changes. To test this, in 196I-I962, we studied urinary ex-
cretion of 17-hydroxycorticosteroids and of ascorbic acid, and checked
the cholesterol content of the blood (F. P. Kosmolinskiy, A. S. Kontsov,
I. G. Dlusskaya, N. A. Vorob'yev, I. M. Khazen, and others). Ascorbic
acid metabolism- -an index of body reactivity (B. A. Lavrov)--is extremely
complex, for it depends on many endogenous and exogenous factors . There
is an abundance of information on the very close relationship between
the metabolism of vitamins (particularly vitamin C), cholesterol, and
corticosteroids .
Our investigations showed that in fliers whose work did not entail
unusual nervous or emotional strain, urinary excretion of ascorbic acid
was within normal limits ( 0.6-1 mg percent). No unusual changes were
noted in corticosteroid excretion under these conditions.
On the other hand, in fliers whose work did entail extreme nervous
and emotional and physical strain, there was increased urinary ascorbic
acid excretion--both after a flight and, in some cases, for 1 or 2 days
thereafter. No such changes were noted in other members of the same
25k
crew who had less responsible jobs. These persons served as a unique
additional control .
Our findings of exceptionally high elimination rate of ascorbic
acid (5, 8, 20, and even 30 times above normal) are at variance with
published data indicating a decrease after flights (V. M. Vasyutoehka n,
Yu. F. Udalov, and others). However, Gadzhiyev's work with mountain
climbers at great heights (1961) yielded data similar to ours.
We noted similar changes under comparable observation conditions,
even when the fliers were given vitamin supplements. Excretion of 17-
corticosteroids increased 2-3 and sometimes 5-6 times. A definite re-
lationship was found between the excretion of 17-OH-KS and that of
ascorbic acid. Blood cholesterol was much higher than in the control
group (l8U and 135 mg percent, respectively). It rose in the pilots
after flights to 196 mg percent, but there was no such rise in the other
members of the crew.
Emotional stress in flight personnel was reflected in the EKG in-
dexes. After flights, the EKG of the captains showed characteristic
changes in the R and T waves and in the S-T interval (P. V. Buyanov,
S. Ye. Komshalyuk, and F. P. Kosmolinskiy, 1962).
The conclusion may be drawn that physiological and biochemical
changes noted in the personnel after long flights with refueling in
the air are directly related to the complexity of the mission.
EFFECT OF PROLONGED LATERAL ACCELERATIONS ON MONKEYS
A. R. Kotovskaya, P. V. Vasil 'yev, B. A. Lapin, S. F. Simpura,
I. S. Grishina and V. I. Kulinskiy
At certain stages in space flight the human organism is subjected
to accelerations which sometimes attain critical values, causing various
functional impairments, particularly, circulatory and respiratory dis-
orders .
Although a substantial number of studies have dealt with the toler-
ance limits and functional impairment of accelerations in man and ani-
mals, many of them deal only with accelerations applied in a lengthwise
direction in relation to the main blood vessels of the body and most
were performed on rabbits and dogs .
The resultant data are undoubtedly of great value, but their plau-
sible extrapolation to man required experiments on monkeys, which are
close to human beings in several anatomical and physiological respects
and can be used for modeling certain pathological processes, particu-
larly in the cardiovascular system, which cannot be duplicated in any
other species of animals (B. L. Lapin, I963) .
The main purpose of this investigation with l6 female monkeys (ll
rhesus monkeys and 5 baboons) was to study cardiovascular and respiratory
reaction to "chest-back" accelerations and to determine the duration of
tolerance of 12 accelerations .
The experiments were performed in a centrifuge with a radius of
7.25 m revolving at the rate of 0.1 g/sec. The body was in a semi-
recumbent position in the chair, the back of which was at a 25° angle
to the ground. A special suit was used to secure the animals to the
chair. None of the animals was anesthetized.
The signs of marked dysfunction of external respiration and blood
circulation (prolonged respiratory arrest or standstill, pronounced
bradycardia or disorders of automatism, excitability and conduction of
the myocardium) served as criteria for the limits of tolerance.
While being rotated, the animals were kept under constant television
observation. Motion pictures were taken and sound communication was
maintained with the cabin of the centrifuge .
Before rotation, the animals sitting in the chair reacted satis-
factorily to the surroundings and eagerly ate up titbits offered them.
No pathological abnormalities were noted in the cardiac or respiratory
indexes. However, all the monkeys had pronounced tachycardia.
Initial reaction to rotation was an orienting response and some
motor restlessness. At the same time, respiration became more frequent
and deeper. As accelerations increased, the animals pressed against
the chair, restless and sometimes screaming. As rotation speed increased,
cardiac and respiratory rates intensified even more. With accelerations
of 12 units, the pulse rate rose from 152-186 to 190-230 beats/min,
while the respiratory rate rose from 2k- 36 to 38-5^ . By the time the
accelerations were halted, the cardiac rate had sometimes slowed by
60-80 beats/min.
Signs of sinus tachycardia with a marked shortening of the EKG
intervals were evident during rotation. The T-P interval changed the
most, for it disappeared as the cardiac rate increased while the T and
P waves merged into a single arc. The QRS interval changed the least.
The Q-T intervals (time of electric systole) changed in accordance with
the cardiac rate.
256
With intense accelerations, the EKG revealed impairment of the
cardiac rate in the form of single, or less commonly group, extrasys-
toles. The electric systoles were chiefly of ventricular and, in just
a few monkeys, of atrioventricular origin. In some cases, they origi-
nated in several places. Most of the animals at this time had sinus
arrhythmia. Some experiments yielded evidence of impaired heart con-
duction in the form of a sinoatrial block.
Appreciable changes were noted in the voltage of the EKG waves.
The P wave during the action of the "square" was less common in the front
and bottom leads (electrode placement by Nebo's method), while in the
back lead it decreased on the average l-l/2 to 2 times as compared with
the original value. In some instances the P wave disappeared almost en-
tirely in the bottom lead. The T wave decreased during the accelerations.
It became isoelectric during the "square", sometimes smoothed out, bi-
phasic, and occasionally negative.
Changes in cardiovascular indexes were transient, disappearing in
the first 10-20 minutes of the aftereffect period, although occasionally
persisting for 20- 3O minutes. The respiratory rate was more or less
restored in the first 10-15 minutes.
These disruptions of bioelectric myocardial activity were caused
by a number of factors, mainly myocardial hypoxia, owing to impairment
of coronary circulation, oxygen deficiency of the blood (dysfunction
of external respiration), and, in some instances, focal hemorrhages.
It is interesting to note that in a study of catecholamines based
on the trihydroxyindole method, the heart of monkeys sacrificed 30
minutes after rotation was found to contain little norepinephrine but
a good deal, sometimes very large amounts of epinephrine. The adrenals
at this time showed very little epinephrine.
When rotation was halted, the animals were generally sluggish and
apathetic. The facial skin was pale while the buccal mucosa was cy-
anotic. Respiration remained rapid and deep. One monkey remained in
a critical condition resembling collapse and died 20 minutes after the
end of the rotation. On dissection it was found to have a fresh myo-
cardial infarct in the anterolateral wall of the left ventricle (V. G.
Petrukhin). The other animals regained their normal appearance 5-10
minutes after the end of the rotation and began to react to external
stimuli, although they remained sluggish and inhibited for 10-15 min-
utes more. After 25- 30 minutes in the vivarium, they became active
and eagerly took food.
General observations of the behavior and condition of the animals
before, during, and after rotation and the results of cardiac and res-
piratory checks showed that monkeys can tolerate accelerations of 12
257
units in a "chest-tack" direction for 1 to h-\/2. minutes (baboons aver-
age 3 minutes and 29 seconds; rhesus monkeys, h minutes and k-5 seconds),
Thus, analysis and comparison of our data with observations on
human beings indicate that monkeys show promise for studying the patho-
genesis of many functional disorders caused by accelerations.
EFFECT OF ACCELERATIONS ON LIVER STRUCTURE
Ye. F. Kotovskiy
Morphological investigations of organs and tissues of animals sub-
jected to accelerations constitute an important activity of aviation
and space medicine. This report presents the results of a histological
study of the liver of animals subjected to lateral accelerations under
experimental conditions .
References in the literature on this subject are few. One such,
by a team of American scientists (Beckman, Ziegler, Diaen, and Hunter,
1953)? dealt with monkey tolerance of accelerations, and found that
chest-back accelerations of about UO g cause foci of degeneration and
regeneration in the liver. Using the method of freezing white rats
in liquid nitrogen right in a centrifuge, Hell and Cranmore (1953) found
that head-pelvis accelerations of 15-19 g cause marked visceral de-
formity and redistribution of vascular blood. The liver is sharply
stretched in the direction of the accelerations; blood flows out in the
same direction. V. G. Petrukhin (1962) investigated viscera of animals
carried on Sputniks 2, h, and 5- He found in the liver venous stasis
and granular, vacuolar, and fatty degeneration of hepatic cells. These
changes disappeared by the 60th day after the flight.
We used 28 male dogs (2 groups of 1^ animals each) weighing 10-15
kg. The first group was subjected to 8-fold accelerations in a chest-
back direction for 3 minutes; the second group, to 12-fold accelerations
in the same direction for 1 minute. Five dogs of the same age and
weight served as the control. Two animals were sacrificed with ether
fumes 1 hour, 1, 3, 7, 15, 30, and 60 days after the experiment. Frag-
ments of liver were taken from the ventral, central, and dorsal portions
of the left lobe. Paraffin and celloidin sections and sections pre-
pared in a freezing microtome (5, 10, and 20u thick, respectively) were
stained with hematoxylin-eosin, Sudan III, methyl green pyronin, and by
Mallory ' s method .
:m
258
Results
The first and second groups showed similar morphological and histo-
logical liver changes, essentially of two kinds: (l) vascular changes,
and (2) changes in hepatic cells and bile duct cells. The vascular
changes apparently began to set in while the animals were in the centri-
fuge. An hour after the experiment, the central, collecting, and, above
all, interlobular veins as well as the intralobular capillaries were
markedly dilated and overflowing with formed blood elements . Many of
them showed leucocytes on the margins, some emigrating to the vascular
wall and surrounding tissue. Some of the large interlobular veins were
destroyed, apparently because their walls ruptured during the experi-
ment. At the site of the destroyed veins and in the surrounding tissue
were the foci of hemorrhages, the size of the liver lobules. Most of
the interlobular arteries preserved their normal structure. A few
showed leucocytic infiltration of the connective tissue. Vascular
changes progressed during the first three days : many of the interlobular
veins were characterized by desquamation of endothelium, wrinkling and
disintegration of nuclei of the smooth-muscle elements, and saturation
of varying portions of the walls with blood. Destruction of the vascu-
lar walls gave rise to "secondary" hemorrhages, usually small and lo-
calized around the blood vessels.
Besides the small perivascular hemorrhages, we noted at this time
other hemorrhages as large as or larger than the liver lobules . Small
hemorrhages were also found within the liver lobules along the sinusoid
capillaries . The impairment of blood circulation was paralleled by im-
pairment of lymph circulation. During the first three days we noted
marked dilatation of the interlobular lymphatics and the appearance of
perisinusoidal spaces between the sinusoid capillaries and trabeculae.
The hemorrhages formed during the first three days were later resorbed.
Macrophages, Kupffer and endothelial cells of the interlobular blood
vessels participated in this process. The protoplasm of all these
cellular forms contained masses of dark brown granules, apparently
hemosiderin pigment. The processes of hemorrhage resorption continued
up to 30 days.
The most pronounced parenchymatous changes occurred during the
first week of the experiment, the period of marked vascular disorders.
These changes were (l) irreversible, (2) degenerative, and (3) rever-
sible dystrophic processes. The first type were local and affected
small portions of the parenchyma near the hemorrhages. The dystrophic
changes, however, involved large portions of the glandular parenchyma,
with death of the liver cells in the region of the hemorrhages. The
more massive the hemorrhages, the larger was the portion of the paren-
chyma undergoing necrosis. In some cases, the blood that flowed out
of the vessels broke up the lobules into individual segments, which
later disintegrated. Small foci of degeneration of liver cells also ap-
peared in the liver lobules near the capillary hemorrhages.
259
Destruction of liver cells in these areas was accompanied by rapid
fatty infiltration and pigmentation of their cytoplasm. Solitary or
small groups of dead liver cells were found in the lumens of the large
interlobular and collecting veins, apparently due to destruction of
their walls. The hepatic cords atrophied near the hemorrhages to about
half their normal thickness because of compression by the extravasated
blood. A comparatively faint leucocytic and macrophagic reaction was
noted in the areas of destroyed parenchymatous elements . The degenera-
tive processes continued for 7-15 days. Reversible dystrophic phenomena
of different kinds, which developed during the first week of the ex-
periment in the liver cells not affected by these processes, were mani-
fested in a decrease in RNA and appearance of fat drops and pigment
granules in the liver cell protoplasm. On the first day of the experi-
ment, pyroninophil granules appeared only in the perinuclear zone of
the protoplasm, the remainder of the cytoplasm not staining with pyronin.
Also, many of the liver cells were characterized by a peculiar process
involving the emergence of nucleoli from the nuclei into the cytoplasm,
which interfered with the synthesis of RNA in the cells. Small drops
of fat accumulated in the cytoplasm of the liver cells, but disappeared
on the 7th day. However, large drops of fat were seen one hour after
the experiment in a few liver cells on the periphery of the lobes. As
a result, the liver cells came to look like fat cells. These cells
eventually degenerated.
In some animals, liver cell cytoplasm was found to contain small
brown granules --apparently bile pigment--which are characteristic of a
congestive liver. The interlobular bile ducts changed considerably.
At first there was fatty infiltration and vacuolation of the cytoplasm
of the cells and occasionally desquamation of the cells in the bile
duct walls. From the 3rd day on, there was a rapid growth of the ducts,
as shown by the formation on the duct walls of numerous cell "buds ",
which then turned into cell strands and tubules which frequently pene-
trated between the hepatic cords deep into the lobules . By the 30th
day of the experiment, the aforementioned changes in the vascular bed
and parenchymatous elements were compensated by hypertrophy and multi-
plication of the liver cells. Occasional instances of mitosis were found
the day after rotation. By the 7th -15th days, the number of binucleate
liver cells had increased by about h percent, and there was evidence
of metaplasia of bile duct cells into liver cells.
The fact that the liver changes and the hemorrhages were much more
common in the dorsal portions, proves that the injurious effect of
accelerations on the liver is greater in the direction in which they
are applied to the body. The changes in both groups of dogs were simi-
lar, although they varied in intensity. The scale of the changes was
far greater in the dogs of the second group. Apparently, under the
given experimental conditions, the degree of liver vulnerability is
related more to the duration of the accelerations than to their intensity.
260
THE USE OF HYPERVENTILATION IN SELECTING CANDIDATES FOR
FLYING SCHOOL
A. K. Kochetov
Hypocapnia, which, together with hypoxia, is regarded as the pos-
sible cause of decreased piloting efficiency at times of great emotional
stress, is receiving considerable attention. Some authors believe that
hyperventilation, which sometimes reduces the pilot's psychomotor effi-
ciency during flight, increases with the speed of the plane (Balke et al.)
Hence, a hyperventilation test is highly important in selecting candi-
dates for flying school or in examining pilots. This functional test
combined with the EEG can be used to detect latent CNS pathological
impairment and to identify individuals with high sensitivity to hypo-
capnia .
Flying school candidates were given EEG's in 196I-I962. The bio-
potentials of the brain were recorded on an 8-channel Al'var oscillo-
graph from the right and left hemispheres- -bipolarly and unipolarly--
from the forehead, temple, and occiput while an EKG was recorded at the
same time in the three standard leads. The men were examined at rest,
sitting in a lighted room with eyes open and closed, and with voluntary
hyperventilation .
Hyperventilation with recording of an EEG can be achieved in a
variety of ways . In the commonest method, the examinee is asked to
breathe as deeply as possible once every 2-3 seconds, continuing for
3 minutes during which time the EEG is recorded. We did not adopt
this method since it is not effective in detecting individual sensi-
tivity to hypocapnia. For example, we observed that some persons,
including well -trained athletes, would complain, after 10-12 respira-
tions, of such disagreeable sensations as parasthesia, dizziness, and
impaired vision, whereas persons tolerant of hypocapnia continued to
feel well for a long time.
The method we used detected individual differences in sensitivity
to hypocapnia. The examinee was asked to breathe deeply at any rate
he wished until he experienced disagreeable sensations, which he re-
ported to the experimenter. The time, noted on the EEG, was recorded
both before and after the sensations for the 30-kO seconds (depending
on the EEG changes) during which hyperventilation continued.
In some examinees, the alveolar air was collected at the onset of
the disagreeable sensations and again when slow oscillations distinctly
appeared on the EEG and the CO content was determined. It was thus
261
possible to determine the degree of hypocapnia when the subjects ex-
perienced disagreeable sensations and to compare the data with the cor-
responding changes on the EEG.
Development of the hyperventilation syndrome was marked by changes
in general condition. Some subjects became pale, others red, with a
sharp increase in the tremor of the closed eyelids and fingers when the
hands were outstretched. Handwriting, in some cases, changed and errors,
including perseveration, occurred.
At different times the examinees mentioned feeling unusual and,
for the most part, disagreeable sensations. In half of the subjects,
the first symptom was paresthesia, "the crawling of small ants" on the
hands or face; in others, the sensations were like "pins and needles"
in the leg.
As hyperventilation continued, the examinees began to complain of
dizziness, general weakness, sensation of "heat or cold", light flashes
or a gray shroud in front of the eyes, etc.
The disagreeable sensations occurred with different degrees of
hypocapnia. For example, in some individuals they arose when the P-CCU
in alveolar air dropped to 28- 30 mm Hg, whereas others did not complain
even when the P-C0 2 dropped to 20-22 mm Hg.
Six persons exhibited pathological symptoms which persisted for 10-
15 seconds after hyperventilation was halted. Four developed lagophthal-
mos; one had spasmodic twitching of the fingers and eyelids; one had a
loss of convergence and smoothing out of the right nasolabial fold.
Three persons were disqualified on the basis of a neurological examina-
tion and EEG data.
In the hyperventilation syndrome, no clear-cut relationship was
noted between subjective sensations and brain bioelectric changes.
While the examinees were experiencing the disagreeable sensations
characteristic of hypocapnia, their EEGs showed a variety of changes:
appearance of solitary or diffuse high-amplitude slow oscillations and
activation of the a or p rhythms. At the same time, some subjects had
EEGs on which the A or © waves became dominant even before they ex-
perienced any disagreeable sensations.
The EEG changes were phasic. At the beginning of hyperventilation
the high-frequency oscillations were activated and, at times, so was
the a rhythm. Later, as hypocapnia set in, the EEG revealed single or
small groups of slow high-amplitude waves (about 200 M-v) of about 3-6
cps, which quickly disappeared after hyperventilation was halted. Thus,
the phase changes in hypocapnia are very similar to the EEG changes de-
scribed in acute hypoxia.
■k : -
262
In conclusion, we wish to point out that the hyperventilation teat,
with simultaneous EEG recording, is sometimes of value in detecting
rather delicate CWS impairments and in identifying persons with low
tolerance of hypocapnia. The latter is important in flying because the
complex situations that arise during flight increase the pilot's emo-
tional stress, a leading cause of hyperventilation.
PRINCIPLES GOVERNING THE OBJECTIVE EVALUATION OF THE THERMAL
STATE OF THE BODY
V. I. Krichagin
Essential in evaluating the airman's body reserves in flight, dur-
ing and after takeoffs, during 24-hour details requiring the handling of
modern special equipment, is an index of his thermal state. This en-
tails ascertaining the degree of pressure exerted by the body's thermo-
regulatory mechanisms in order to forestall serious disorders caused by
overheating or supercooling and to determine the varying effects of this
pressure on efficiency. All findings indicate that the objective and
subjective data pertaining to the thermal state should be comprehen-
sively evaluated.
1. General Evaluation of Adaptability to Environmental Conditions
On the basis of published data and personal observations, we pre-
pared a table that provides an estimate of the possibility of maintain-
ing body heat balance under various thermal conditions . It may also be
used for provisional analysis of the experimental data from the thermal
gradients between the surface of the, skin and clothing, air and surround-
ing objects in relation to thermal insulation of clothing, etc.
2. Evaluation of the Thermal State from Objective Characteristics
On the basis of numerous reports by Soviet and foreign investigators
and our own investigations, we suggest these gradations of thermal states
(in a condition of relative rest).
(a) Comfortable state: complete absence of subjectively sensed in-
formation on the thermal state (absence of a dominant heat focus of
excitation in the cerebral cortex) .
263
Objective data:
(l).Net weight loss (by imperceptible perspiration- -50 ± 10 grams/
hour) .
(2) Absence of visible signs of perspiration.
(3) Rectal temperature --37 + 0.k°.
(h) Axillary temperature --36. 5 ± O.5 .
(5) Changes in rectal or axillary temperature- -by no more than
+0.2° per hour.
(6) Weighted mean skin temperature-- 33. 3 +1.0 C.
(7) Difference between trunk and extremities temperature within
3 + 0.5° C.
(8) Temperature and humidity of underclothing air within the limits
of evaluation of heat sensation from underclothing air.
(b) State of Slight Pressure Exerted by the Physiological Mechanisms
That Block Heat Emission: mild sensations evaluated as "cool"; often
regarded as "comfortable" in the presence of a stronger functioning
dominant or good heat protection of the extremities (a basic receptor
field). Coolness is clearly perceived only after a loss of 3O-UO large
calories of heat, i.e., affer a long period of time.
Objective data :
(1) Slight pallor; collapse of surface veins on forehead and ex-
tremities .
(2) Net weight loss --at or below the comfort level.
( 3) Rectal and axillary temperatures drop at the rate of no more
than 0.2° per hour to a point below the comfort level.
(k) Weighted mean skin temperature — 3I.3 + 1° C.
(5) Difference between trunk and extremities temperature--^. 5 +
0.5 C.
(6) General physiological indexes (pulse, respiration, metabolism,
etc.) remain virtually unchanged.
J i
261*
(7) Temperature and humidity of underclothing air fall in region
1 on the table mentioned above .
(c) State of Strong Pressure Exerted by the Physiological Mechan-
isms That Block Heat Loss by the Body: distinct sensation of general
and local coolness, felt when the body loses 7O-9O kcal of heat; re-
flects a more rapid body heat loss.
Objective data:
(1) Greater systemic pallor, sometimes local reddening of exposed
parts of the face and hands with some bluish (congestive) tinge.
(2) Rectal temperature --35. 5 + O.U° C.
(3) Weighted mean skin temperature- -29- 3 + 1.0° C.
(k) Difference between trunk and extremities temperature- -from 5 "to
15 c.
(5) 10-15 percent increase in metabolic rate without shivering and
20-50 percent increase with periodic shivering.
(6) Acceleration of pulse by 10-15 beats/min.
(7) Temporary stabilization of temperature characteristics after
inclusion of chemical thermoregulation.
(d) State of Marked Coolness of the Body (Followed by Breakdown of
Compensation) : definite sensation of "very cold", which develops after
body loses more than 180-200 kcal of heat; reflects rapid body heat loss.
Objective data:
(1) Drop of rectal temperature below 35 C.
(2) Progressive drop of weighted mean skin temperature below 28° C.
(3) Progressive drop of extremities temperature until loss of skin
sensitivity and complete freezing starting with the hands and feet.
(h) Sharp temporary increase in metabolic rate to 3OO and corre-
sponding pulse acceleration to 120 beats/min, which stops after rectal
temperature falls below 33-5-3^.0° C.
(5) Stable temperature characteristics (temporary breakdown of
compensation) .
265
Overheating can "be differentiated in about the same way.
(a) State of Slight Pressure Exerted by the Physiological Mechan-
isms That Increase Heat Emission by the Body: a sensation of "warm";
rather sharply distinguished from the comfortable state by increased
heat emission due to evaporation.
Objective data :
(1) Slight reddening of the skin, veins distinctly visible on the
forehead and extremities .
(2) Rectal temperature --37. O-37. 2° C.
(3) Axillary temperature- -36. 6- 37. 0° C.
(h) Increase in net weight loss of about 250 g/hour; perspiration
evident on various parts of the body.
(5) Weighted mean skin temperature --34. 9 + 0-7° C.
(6) Difference between trunk and extremities temperature --1 .8 +
0.7 C.
(7) Acceleration of pulse by 7-10 beats/min.
(8) Temperature and humidity of underclothing air fall in region 3.
(b) State of Strong Pressure Exerted by the Mechanisms That In-
crease Heat Emission by the Body: distinctly unpleasant sensation of
"hot".
Objective data :
(1) Marked reddening of the skin, swelling of the surface veins of
the face and extremities.
(2) Rectal temperature unchanged or elevated only O.3-O.U C.
(3) Net weight loss due to perspiration evaporating or running
off at the rate of 250-U00 g/hour.
(k) Excessive perspiration, wetting clothing.
(5) Weighted mean skin temperature-- 36 + 0.6° C.
(6) Difference between trunk and lower extremities temperature
less than 1° C (skin temperature of the lower extremities and forehead
1*1
Si
266
is characteristically higher than that of the upper extremities and
trunk, respectively) .
(7) Acceleration of pulse by 8-15 beats/rain.
(8) Temperature and humidity of underclothing air fall in region 4.
(c) State of Sharp Pressure Exerted by the Mechanisms That Increase
Heat Emission by the Organism (Followed by Breakdown of Compensation) :
severe, intolerable sensation of "very hot"; indicates ambient temperature
is beyond the adaptive capacity of the body.
Objective data:
(1) Marked reddening of the skin and swelling of the veins (pal-
lor upon decompensation).
(2) Net weight loss of from 400 to 2000 g/hour, hidrosis.
(3) Weighted mean skin temperature- -more than 36.6 C.
(4) Progressive elevation of rectal temperature- -by more than 0.3
C per hour.
(5) 15 percent increase in metabolic rate (with elevation of am-
bient temperature each degree above 37°) •
(6) Acceleration of pulse by more than 15 beats/min, maximum- -li+0
beats/min.
(7) Stability of temperature characteristics temporary, maintained
from 30 minutes to 8 hours, depending on severity of environmental
conditions.
(8) Temperature and humidity of underclothing air beyond the zone
in which a balance can be maintained.
The limit of tolerance is reached when the body accumulates excess
heat amounting to 1.4-3 kcal per kg of weight (100 kcal for an adult male
weighing 70 kg).
The data outlined above can be used as criteria for evaluating the
body's heat state. Allowance has to be made, of course, for individual
deviations and exceptional cases.
267
CHANGES IN SOME PHYSIOLOGICAL FUNCTIONS RESULTING FROM EXPLOSIVE
DECOMPRESSION
A. G. Kuznetsov, A. S. Tsivilashvili and A. R. Mansurov
It is well known that cabin depressurization in high-altitude
planes subjects the crew to pressure drops. The drop may be slow (motor
failure, slight damage to the cabin wall) or rapid (explosive decompres-
sion: rupture of the canopy, severe damage to the cabin wall). Explo-
sive decompression causes significant physiological changes, varying
with the magnitude, rate, and number of pressure drops.
In this investigation of physiological effects of large and rapid
pressure drops, dogs and rabbits were placed in a specially constructed
chamber in which barometric pressure was reduced for 0.3-0.00lj- second.
The parameters of explosive decompression were predetermined. Procedures
included: recordings of respiration (rate and rhythm), biopotentials of
the respiratory muscles, EKG, and arterial blood pressure; roentgeno-
graphy and cinefluorography (8-l6 frames per second) of the thoracic
and abdominal organs and roentgenokymography of the diaphragm and ribs
of intact animals; action currents from the diaphragm and vagus nerves
of anesthetized dogs and nonanesthetized rabbits.
Immediately after the pressure was reduced, all animals experi-
enced respiratory arrest (apnea) lasting 2-15 seconds, which sometimes
returned for 3-U seconds after the first inhalation. Although respira-
tion was then restored, its rhythm and depth were usually impaired- -
shallow breaths followed by deep ones . Normal rhythm and depth were
generally restored as the animals were being lowered to an "altitude"
of 5OOO-6OOO m.
Suspension of respiration for several seconds after explosive
decompression is probably reflex in nature, the result of receptor
stimulation caused by distention in lungs and gastrointestinal tract.
Fluorograms of animals with body unbandaged made 0.02 second after
pressure drop revealed various changes, chiefly in the lungs, diaphragm,
and heart, as well as a marked enlargement of gastrointestinal gas
bubbles and formation of vapor and gas in the organs and tissues.
Roentgenokymograms of the diaphragm and ribs showed marked im-
pairment of external respiration. In most cases, respiration was very
frequent and more shallow than at the start.
There are references in the literature to the neuroreflex nature of
respiration inhibition by creating excess lung pressure. A. G. Kuznetsov,
G. V. Altukhov, and N. A. Agadzhanyan demonstrated in nonanesthetized
r,
268
animals that increased intrapulmonary pressure following vagus transec-
tion does not inhibit respiration. However, since no direct experimen-
tal data were obtained during explosive decompression, a series of ex-
periments was run on nonanesthetized rabbits with recording of the
action currents of the vagus nerves, which invariably yielded an inten-
sified flow of impulses as soon as the pressure was reduced. Bioelectric
activity generally remained high throughout the period of apnea. Re-
sults showed that the period of apnea was characterized by a heavy flow
of impulses through the vagus nerves, the maximum occurring 2 seconds
after explosive decompression.
It was of some interest to determine the state of the respiratory
center at a time when there were no respiratory movements of the thorax,
for which the biopotentials were recorded from the diaphragm. In all
the experiments, impulses flowed steadily from the diaphragm after
explosive decompression against a background of apnea. These data imply
an obvious lack of inhibition of the respiratory center under these con-
ditions. Marshak and Mayeva (1961), who observed a similar phenomenon
in animals exposed to hypocapnia, came to the same conclusion.
A study of the biopotentials of the intercostal muscles and obliquus
abdominis externus and internus showed that in all cases explosive de-
compression was followed in a few seconds by a continuous flow of im-
pulses from these muscles. Amplitude and duration of the impulses
varied with magnitude and speed of the pressure drop: substantial with
great intensities and speeds, achieving in some experiments 300-i)-00 mv
and 3-I1- seconds, respectively. Maximum EMG amplitude occurred I-3
seconds after a pressure drop, then gradually decreased until it dis-
appeared entirely only to reappear with restoration of thoracic res-
piratory movements. Muscular contraction, for the most part, coincided
with exhalation.
Other authors (A. G. Kuznetsov, M. I. Vakar, V. S. Gurf inkel ' , et
al., 1953) first noted the stimulation of a flow of continuous impulses
from the respiratory muscles by explosive decompression—apparently a
protective reflex in response to excess pressure arising in the lungs
and gastrointestinal tract. It is worth noting that vagus transection
did not obliterate the biopotentials of the respiratory muscles, indi-
cating the vagus nerve is not the only stimulus of this reflex. Other
causes are indirect pathways represented by the nerve fibers that form
part of the sympathetic chain, and the proprioceptors of the muscles
and ligaments in the thoracic skeleton.
It was later found that explosive decompression intensifies the
biopotentials not only from the respiratory muscles but from muscles
not directly involved in respiration, particularly the femoral muscles.
269
In most of our tests, explosive decompression was followed in a
few seconds by a decrease in the cardiac rate (bradycardia), a result
observed also by other authors (Hitchcock, 1953; Gelfan, Nims, and
Livingston, 1950; others). Bradycardia in animals subjected to explo-
sive decompression was more pronounced 2-3 seconds after the pressure
drop. Like apnea, bradycardia is reflex in origin and caused by dis-
tention of the lungs and gastrointestinal tract due to excess pressure.
To prove its reflex nature, vagus transection and exclusion of the
parasympathetic nerves by atropinization were performed experimentally:
in all animals, the cardiac rate generally increased after explosive
decompression; occasionally it remained unchanged.
As mentioned above, arterial blood pressure was measured in some
of the rabbits. In the carotid artery at the time of explosive de-
compression, blood pressure increased by about 50-70 mm Hg. After the
pressure drop, blood pressure usually fell within 1-2 seconds to a
lower level than before ( 70-90 mm Hg below normal). At the same time,
pulse pressure rose sharply to the point of total disappearance of the
pulse oscillations.
The transient elevation of arterial pressure during explosive de-
compression was apparently due to the mechanical effect on the blood
vessels of the mediastinum. The subsequent decrease in arterial pres-
sure was probably reflex in nature and caused by the marked elevation
of intrapulmonary and intraabdominal pressure following explosive
decompression. This assumption found support in the experiments with a
vagotomy, in which, after a temporary decrease, arterial pressure again
rose and remained high for several minutes. This was obviously caused
by exclusion of the impulses proceeding to the CNS from the lungs and
gastrointestinal tract through the vagus nerves, which were transected
here .
The data show that explosive decompression causes, in a very short
time, major changes in main physiological functions. These changes are
reflex in nature and vary with the type of decompression.
270
CHANGES IN RESPIRATORY AND CARDIOVASCULAR FUNCTIONS AFTER PROLONGED
EXPOSURE TO LOW BAROMETRIC PRESSURE
A. G. Kuznetsov, N. A. Agadzhanyan, Yu. P. Bizin, N. I. Yezepchuk,
I. R. Kalinichenko, L. I. Karpova, I. P. Neumyvakin and M. M. Osipova
Conquest of outer space must await solution of many biomedical prob-
lems especially those relating to the gas exchange and cardiovascular
effects of prolonged exposure to rarefied atmosphere. There is a
limited number of published reports on the subject (D. K. Ivanov, V. B.
Malkin, V. L. Popkov, Ye. 0. Popova, and I. N. Chernyakov, I96I; V. P.
Zagryadskiy et al., 196l; Welch, Morgan, and Thomas, 1961).
This project involved extended exposure of two subjects to low
barometric pressure corresponding to an altitude of 7000 m (with a
partial pressure of oxygen of 150-160 mm Hg), and study of the dynamics
of gas exchange, cardiovascular function, and peripheral blood. Gas
exchange was investigated while the subjects were resting (basal metabo-
lism), and during and after physical exercise (h-0 squats in 2 minutes)
using the combined Douglas -Haldane method and spirometabollograph. For
fuller understanding of respiratory function, measures were taken of the
minute ventilation (MV), vital capacity, and volume of reserve and ad-
ditional air.
For comparability, the value of the MV and oxygen utilization were
reduced to 0° C and 76O mm, and a correction was made to allow for the
respiratory coefficient (RC) effect. Due to the lack of tables showing
values of the coefficient (F), we compiled a conversion table to suit
the rarefaction conditions in order to bring the gas saturated with water
vapor to a dry state, 0° and 760 mm Kg.
In our investigation, prolonged exposure to an artificial atmosphere
reduced oxygen utilization by subjects at rest by 6-17 percent the first
month, and by 3^-36 percent the second month; somewhat less pronounced was
the decrease in release of CO . As a result, the respiratory coefficient
gradually rose from 0. 75-0.82 to 0.97-1.1.
The amount of heat emitted dropped 7.5-lU percent the first month,
and 28-3I1.5 percent the second month. The MV decreased 5-10 percent the
first month, and 9-5-25 percent "the second month.
By the end of the experiment, the cardiac rate decreased by 8-10
beats (20 percent) on the average, and the maximum and minimum arterial
blood pressure decreased by 10-16 percent and 7-8 percent, respectively.
271
The fact that the pulse rate decreases after prolonged exposure to
low barometric pressure has been noted also by other authors (D. I.
Ivanov, V. B. Malkin, et al., 196l; A. D. Seryapin, 196l; others).
In analyzing these data, it should be borne in mind that the cho-
linergic action of the vagus nerve is impaired under conditions of rela-
tive adynamia. The predominance of the adrenergic action of the sym-
pathetic nerve results in metabolic changes in the blood vessels and
tissues (Raab, 1955).
The literature has references to changes in blood pressure after
exposure to low barometric pressure (Morgan, Ulvedal, and Welch, 1961).
These changes are reflected in decreased diastolic pressure with simul-
taneous impairment of myocardiac excitability, as shown on the EKG.
Our experiments failed to detect any significant EKG changes in subjects
remaining a long time at a high altitude; there was merely a slight
decrease in the maximum values of the R and P waves.
In checking the functional capacity of the body in response to
measured physical exercise, the orthostatic and Valsalva tests were made
in order to ascertain the degree of deconditioning. Results show that
the reactions to the functional tests varied with the duration of the
experiment. At the end of the experiment, there was generally a con-
siderable increase in the pulse in response to measured physical exer-
cise. At the 'same time the periods of pulse restoration to the original
level lengthened while "negative phases" of blood pressure developed,
a phenomenon regarded by most authors as an indication of cardiovascular
fatigue--autonomic-vascular instability (S. S. Mindlin, I93O; Gorinev-
skaya, lQkk; B. A. Ivanovskiy, 1935)- These events were probably brought
about by general asthenia, decreased vascular tone caused mainly by in-
sufficient motor activity, and diminished flow of afferent impulses.
In addition to investigating gas exchange and the cardiovascular
system, we examined the peripheral blood supply under rarefied atmos-
pheric conditions. Owing to extreme instability, the blood system re-
flects at the same time all the physiological changes resulting from
exposure to a variety of environmental factors--physical, chemical,
mental, etc.
We found that the hematological changes were very slight--only a
trivial increase in the erythrocytes, reticulocytes, and hemoglobin.
The increase in erythrocytes and hemoglobin was probably caused by blood
clotting, which may occur at high altitudes following disruption of the
water balance. This mechanism of erythrocytosis cannot be ruled out en-
tirely, but it does not seem to be the only one.
The leucocyte count was within normal limits. The absolute number
of eosinophils in the second half of the experiment was 1-1/2 to 2 times
below the original values. An investigation of the phagocytic activity
272
of the neutrophils showed that the phagocytic number and phagocytic in-
dex increased by the end of the experiment. The increase in phagocytic
activity was preceded by an inhibition phase .
The above -de scribed changes in gas exchange, like the other physi-
ological functions, were largely due to hypodynamia, which caused the
metabolic level to drop. This was shown by the fact that the gas-
exchange function became virtually normal 8-10 days after the end of the
experiment and the subjects resumed their regular activities.
It is our view that in itself the factor of low barometric pressure
(3O8 mm Hg) with normal partial pressure of oxygen (150-160 mm Hg) has
no significant effect on the body, specifically, on the gas exchange
function. If rarefaction has some biological effect, it is probably
realized through water metabolism.
CHANGES IN THE VECTORCARDIOGRAM OF FLIGHT PERSONNEL IN
EARLY STAGES OF HYPERTENSION
Ye . I . Kuznetsova
Vectorcardiography has not yet found the application it deserves
in aeromedical practice. Only a few reports are available in which this
method has been used in examining individual personnel . In our work we
have tried to find earlier supplementary criteria for evaluating the
condition of the cardiovascular system in flight personnel.
Our report presents material based on data from a study of 55 in-
dividual fliers, 30 to k-9 years old, of whom 25 were normal and 30 had
a diagnosis of hypertension in the first stage A-B according to L. A.
Myasnikov's classification.
All individuals were given a general clinical examination. , Vector-
cardiograms were first analyzed by comparing them with electrocardio-
graphic data and data from X-ray examination, then recorded by the 5-
plane system of I. T. Akulinichev. Results were treated statistically
for reliability and incorporated into the table .
The table makes it evident that the average value of the maximum
vector of the QRS loop in hypertensive patients has a tendency to in- '
crease in all 5 planes. This apparently stems from an increase in the
difference of the bioelectric field of the myocardium.
273
Average Data of Vectorcardiogram Analysis
Planes I II HI IV V .
Groups
examined
Healthy 29-1 30-2 29-6 21.2 Ik.'Z
-n • * 4.1, ™-,c, Hypertension,
Basic axis of the QRS J. . , ' _. _ _, fi _i, r 0o ,= -, = a
loop in five planes first de S ree 3^-3 3^-8 3^-6 2 3 -5 15-8
(Akulinichev method) B
Reliability 90 90 90
Healthy 97-^ 85.3 88.5 -71.8 -86.3
Angle of deflection of
the basic CiRS axis in Hypertension,
degrees by planes ^st de § ree 91-U 86.7 93-2 -83.O -91-6
Reliability 90 - 90 90
Healthy 8.0 8.6 7-9 6-6 3-7
Basic axis of T loop Hypertension,
in mm first degree 7-2 7-5 7-5 6.6 1+.6
A-B
Reliability - 90 - - 95
Healthy 93-3 92-9 72.6 -95-8 -80.5
Angle of deflection of Hypertension,
the basic axis of the £™t degree 93-3 92-9 83.6 -90.5 -91-3
T loop in degrees
Reliability _ - 98 - 90
Healthy 6.3 9.3 I3.O 8.5 10. 5
Angle QRS-T in S^??!*!?:!*'
degrees
first degree 15.8 I3.8 15.6 15-9 21.2
A-B
Reliability 99 - - 90
Note : Reliability is expressed in percent; plus values are expressed
without the sign.
Hill
■SI
27^
It must be noted that with the increase in the maximum axis of the
QRS loop, a simultaneous deformation of this wave is observed in a
number of cases because the formation of an additional axis resulting
from a rise mainly in its terminal deflection, which also leads to a
broadening of the loop. A broadening of the loop is noted quite fre-
quently in projections I, II and IV in our material.
An additional axis is frequently seen isolated only in projection
IV, which supports the concept, judging from the literature, that the
indicated changes develop earliest in the apical region.
In most hypertensive patients, the direction of registration of the
QRS loop is counterclockwise in projection I and clockwise in projection
IV. These data testify to the tendency of the vector components of the
period of depolarization to deflect to the left and back, which also
supports our feeling concerning the primary localization of the process,
conditioning the difference in bioelectric potentials in the region of
the apex of the heart. In patients in the initial stage of hypertension,
however, a regular change is noted in the direction of the vector of re-
polarization in plane III, i.e., from the front back and to the left.
Besides, the integral vector of repolarization is regularly increased
in projection V, and has a tendency to change in projection II. This
can be regarded as an initial intensification of metabolic processes
of the myocardium.
Thus, vectorcardiography makes it possible, at very early stages
of hypertension, to determine the fine metabolic changes which lead to
a disturbance of the myocardium's regular bioelectric polarity.
EKG CHANGES IN FLIGHT PERSONNEL AFTER PROLONGED NONSTOP FLIGHTS
N. M. Kulikova
The execution of prolonged nonstop flights by the crews of turbo-
prop airplanes introduces the question of the degree of fatigue of
flight personnel in fulfilling such trips.
It is known that a pilot's ability to work is determined to a sig-
nificant degree by the functional condition of his CNS, cardiovascular,
and other systems . From the point of view of the cardiovascular system
definite negative shifts are not infrequently observed during flight
activities. Definite changes, produced by fatigue, were detected during
EKG examinations. Thus, A. E. Krimsteyn examined flight personnel and
275
noted that in periods of biweekly and monthly flight loads, changes ap-
peared in the EKG characteristic of the recovery period after severe
hut "bearable" physical stresses. The author points out that two or
three flights evoked changes corresponding to a significant but "bear-
able" stress. In daily stress the EKG changes for pilots corresponded
to moderate or significant but well endured loads, while for navigators
the changes corresponded to highly wearying or excessive flying loads.
The influence of fatigue on the character of the EKG was also shown
in the work of Teng Su-I, where the EKG of practically normal students
at the time of an examination session, showed simultaneously and in
parellel an increase in the systolic index with shortening of the cardiac
cycle (E-R and QRST).
The present work sought to determine by the EKG method changes in
the cardiovascular systems of flight personnel who were carrying out 8-9
hour nonstop trips in turboprop planes on the Moscow-Khabarovsk-Moscow
route. The EKG's were recorded 1 hour after the plane landed in the
airport, 2k hours after rest in Khabarovsk, and 2-3 days after rest in
Moscow. The recording was done at the prophylactic airports in Khabar-
ovsk and Moscow on the EKP-60 apparatus with 3 standard leads and in the
third lead at the height of a deep breath. The EKG was recorded both
at a resting state (in a lying position) and after a stress dosage (15.
knee bends in the course of 20 seconds). In all, 226 EKG's were regis-
tered and analyzed by studying the frequency and character of the rhythm,
the duration of intervals (P, PQ, QRS, QRST), the value of the systolic
index, the direction of the electrical axis of the heart (according to
the table of Pis'menniy), the voltage of the P, R and T notches in the
3 standard leads .
EKG indexes for all members of the crews during observation both
after flight and after rest did not exceed the limits of normal, physio-
logical values. Comparison of initial data (after 2-3 days of rest)
with the EKG data after flight revealed the following.
After flights, all the cabin captains and the majority of the co-
pilots and navigators maintained a sinus normal rhythm. Four of the
copilots in the resting condition registered a sinus arrhythmia which
disappeared after a load dosage, and 6 individuals showed a sinus ar-
rhythmia after a stress.
After 8-9 hour nonstop flights, the majority of the cabin captains
(70 percent) in a resting condition presented an increase in frequency
of rhythm of the heart contractions, averaging 10 beats per minute.
The majority of the copilots and navigators (66.6 percent) presented a
decrease in frequency, averaging 9 beats per minute. After a stress
dose, almost all crew members showed an increased frequency in the
276
rhythm of heart contractions, expressed in almost the same degree in
the cabin captains and the rest of the crew.
Intraatrial and intraventicular conductivity in all of those ex-
amined did not change. A slowing of the atrioventricular conductivity
by 0.02 second was noted in 1/3 of the cabin captains. In the remaining
members of the crew no change was observed in atrioventricular conduc-
tivity. After a stress dosage, no disturbances were registered in the
conduction of the sinus impulse by the conducting system of the heart.
The value of the systolic index (Si) for the majority of the crew
members agreed with the normal for the given rhythm. In some of the
cabin captains examined it exceeded the normal. Thus, in the resting
state in 22 percent of the cabin captains the SI exceeded the normal
by 6-I5 percent. After a physical stress the SI value for the cabin
captains exceeded the normal in a large percent of the cases (h-7 per-
cent). In 20.5 percent of the cases an increased SI was noted in the
copilots and navigators (6-10 percent in comparison with the normal
for the given rhythm) .
After a flight the majority of the flight personnel examined at a
state of rest showed a counterclockwise displacement of the electrical
axis of the heart (EAH). Thus, in 75 percent of the cabin captains
the EAH shifted 12° on the average; in the copilots and navigators a
similar deflection was noted in 61.9 percent. After a stress dosage the
EAH in the majority of the crew members shifted 9° clockwise on the
average, a larger percentage of the cases in the cabin captains (78.lt.
percent) than in the other crew members (61.3 percent).
Changes in the voltage of the EKG notches appeared as a lowering
of the value for the T notches. Thus, in 1/3 of the cabin captains, a
lowering of 0.5-1 mm in the T notches was noted in the first and second
leads. At the same time, the copilots and navigators registered an
increased T voltage in the three standard leads (Tj to 1 mm in 42.9 per-
cent; Tjj to 1.4 mm and T-qj to 1.1 mm in 66.1 percent). After a stress
dosage the majority of the flight personnel presented a decrease in the
voltage of the EKG notches, expressed mostly by the cabin captains.
The changes referred to above in the frequency of the heart rhythm
after flight are probably associated with changes in tone of the extra-
cardial nerves. The lengthening of the auriculo-ventricular conductivity
with simultaneous acceleration of the rhythm of the heart contractions,
noted in the cabin captains, can be viewed as the result of a disturb-
ance in the usual correlation of the tone of the extracardial nerves,
or as the result of a lowering of the conductivity of the atrioventricular
node under the influence of fatigue . The counterclockwise shift of the
277
EAH can be related to an increase in bioelectrical activity of the left
ventricle associated with changing conditions in the blood circulation
as a result of a load such as a prolonged nonstop flight. The tendency
to post-flight rhythm acceleration noted in the cabin captains, with
simultaneous increase in the systolic index and decrease in the T notch
voltage, testifies to a lowering of the functional capacity of the myo-
cardium, probably as a consequence of post-flight fatigue . The post-
flight increase in the T notch voltage with simultaneous shortening in
the rhythm frequency noted in the copilots and navigators can be related
to the influence of hypoxia on the myocardium.
The following conclusions can be drawn from a generalization of the
results of EKG examinations of flight personnel after prolonged nonstop
flights :
(a) EKG indexes in all crew members after prolonged nonstop flights
do not exceed the limits of normal physiological values.
(b) After 8-9 hour nonstop flights, cabin captains both in a state
of rest and after a stress dosage present changes in the EKG, indicating
a lowering of the functional capacity of the myocardium, which are more
expressed than in the other crew members.
(c) Changes noted in the EKGs after flights possessed a functional
character; after 2k hours of rest the observed shifts were fewer in
number and completely disappeared after 2-3 days rest.
(d) Post-flight changes in the EKG are to be regarded as the effects
of fatigue arising as the result of stresses such as prolonged nonstop
flights.
PARTICIPATION OF L. A. ORBELI IN THE DEVELOPMENT OF THE
PROBLEM OF COSMIC PHYSIOLOGY
A. V. Lebedinskiy
The organization of experiments which were inaccessible to earlier
workers in the field represents notable milestones in the development of
physiology. The flight of man into the cosmos is such an experiment, the
significance of which for the development of biological sciences has not
yet received its full evaluation. As a result of this experiment mankind
has savored not only the unconquerable power of scientific thought which
-■m
278
preserves the life of man on our entire planet, but also the wonderful
possibilities of perfecting his organism by producing a healthy exist-
ence for it under unusual conditions .
One of the important reasons for success has been the development
according to plan of the unfolding of the preparatory scientific -work,
the spirit of genuine collectivism in this gigantic labor. It would
be simply unpardonable, summing up the results now, to forget its ori-
gins in the science of our country.
Thoughts about the possibility of cosmic flight were born long ago
in the minds of scientists who were able to combine exact knowledge
with scientific fantasy. Biologists will always hold dear the names of
Tsiolkovskiy, the Schluesselburger Nikolay Morozov, who pondered over
a number of important biological facets of this experiment. However,
the immediate organizer of biological preparation for cosmic flight,
who turned first to biology, was N. A. Rynin, the initiating founder
of the Section of Aviation Medicine, NIAI, the actual organizer of
which was A. A. Sergeyev. A participant in the development of problems
studied by the Section was one of Pashutin's eminent students, the phar-
macologist A. A. Likhachev. In this Section, and at the Department of
Physiology of the S. M. Kirov Military Medical Academy, headed by Acade-
mician L. A. Orbeli, work was accomplished to complete the medico-
biological support of the flight of the stratosphere balloon USSR-2,
piloted by P. F. Fedoseyenko and which had on board the physicist I. D.
Usyskin and the engineer A. B. Vasenko.
The scientific knowledge yielded by the ascent of the stratosphere
balloon USSR-1 to a height of l8, 600 meters (September I933) and USSR-2
(January I93U) sparked the prominent research role of the problems of
"stratospheric medicine, " which was the genuine precursor of cosmic
medicine. They found their reflection in the work of the Ail-Union
Conference on the Study of the Stratosphere, convened in 19 35 by the
AS, USSR.
One report (by L. A. Orbeli) that received great attention at the
Conference, proposed solutions of a number of fundamental problems,
which are still important to research workers in the field of cosmic
biology and medicine.
Orbeli r s basic idea consisted of a demand for the cooperation of
the strong features presented by the various specialties and for their
realization in a definite plan. But, since L. A. Orbeli was a research
scientist, for whom it was organically unusual to stop at wishes alone,
tried to map out the basic content of the proposed plan of research.
His work plan followed from the basic goal which he presented to the
physiologists in providing for the flight of man into the stratosphere.
It consisted of making it possible for the stratonaut to "actively
279
introduce himself" into space beyond the earth's limits, and, while
under these unusual conditions, to continue to be a scientist investi-
gating the unknown. This "activity" under any conditions was the motto
of L. A. Nedarov the same man to whom we find pages dedicated in the
book "Dramatic Medicine" by Hugo-Glazer, which describe his personal
participation in experiments set up to study the effect of increased
atmospheric pressure on the organism.
The scientific facts discovered by L. A. Orbeli led to the convic-
tions that it is possible for a man to preserve his activity under con-
ditions difficult for the organism. It is well known that L. A. Orbeli 's
world outlook was formed in Pavlov's laboratory during many years of
extended personal contact with his teacher. The basic feature of
Pavlov's teaching that won him over at once and retained his scientific
interest for a long (and has the most immediate connection with the
theme of our report ) .
Of course, the basic element of Pavlov's creative work was the dis-
covery pertaining to higher nervous activity. This discovery not only
let to the establishment of the laws of behavioral reactions and of the
intricate reflex regulation of functions, but also presented very con-
vincing natural scientific evidence of secondary consciousness. Simul-
taneously, especially from the time of the discovery of the second signal
system, it was a fascinating presentation of the evolution of the adaptive
mechanisms of the animal organism, and of the enormous possibilities for
its perfection.
Research showed that changes of this kind can proceed in the more
vitally important organs; the substrate of these actions is the nervous
system as I. P. Pavlov had already shown in the eighties of the last
century in connection with the influence of a reinforcing nerve on the
heart muscle. These very experiments guided L. A. Orbeli to the setting
up of experiments to study the influence of sympathetic innervation on
the exhausted skeletal muscle.
We often underestimate the impressions which the Orbeli-Ginetsinskiy
study made on the development of scientific inquiry in those years. It
clearly illustrated the possibility of functioning under difficult con-
ditions, outside the framework of the usual laws of regularity, beyond
the apparent limits of working capacity. The greater adaptive capacities
of the mechanisms of higher nervous activity, discovered by I. P. Pavlov,
the concrete facts about the adaptive capacities of the organs and sys-
tems of the organism revealed by L. A. Orbeli, and, finally, the cor-
tical mechanisms of mobilization of the adaptive capacities of the or-
ganism as a whole (which were systematically studied by K. M. Bykov)
are different but necessary links in the concept of human physiology
under extreme conditions, of which cosmic medicine represents a higher
practical application.
280
Let us return to the Orbeli report, which is one of the pioneer
events in this field. In speaking of the plan of work in the coming
field of physiology of stratospheric and cosmic flights he pays due
attention to the need for broad study of diverse biological specimens
under these conditions. But L. A., in addition, and with all determi-
nation, emphasizes the essential role of physiology — it is, primarily,
the study of highly developed organisms, and, in particular, of man.
As we have already said, these investigations must be subordinated first
of all to one basic task- -support of the active intrusion of man into
stratospheric space. This indicated the need to establish those con-
ditions of flight in which the mental capacity of the man-investigator
is preserved completely, with full comprehension of the entire gamut of
his experience and sensation. From this flowed the task of studying
the analytical functions of the stratonaut and, primarily, the condi-
tion of his visual functions.
It is almost 30 years since the work of the first Conference on
the study of the stratosphere. The conditions of cosmic flight turned
out to be somewhat different from those of stratospheric flight. Study
of stratospheric flight revealed ways of physiological support of a stay
within the hermetically sealed space of the stratospheric cabin and of
living inside a diving suit (V. A. Spasskiy, A. P. Apollonov, M. P.
Brestkin). This showed once more the need to organize and achieve a
practical experiment involving the preparation of an astronaut, and
realization of a method to observe the state of his organism in the
process of flight. The pertinent materials are well known and there
is no need to dwell on them in more detail. It must only be emphasized
that this indisputable success which fell to the lot of our scientists
in the organization of control over the condition of the organisms of
our astronauts flows to a significant degree from the collective way,
characteristic of our science, of developing scientific problems, the
cooperation of biologists and engineers about which L. A. talked in
his speech.
The scientific results obtained from the cosmic flights of Yu.
Gagarin, G. Titov, A. Nikolayev and P. Popovich have been published
(V. V. Parin, N. M. Sisakyan, V. N. Chernigovskiy and V. I. Yazdovskiy,
and others), and their value is undoubted and indisputable. The gen-
eral conclusions which can already be drawn from these foundations
have no less significance.
When he stood before the Conference, L. A. Orbeli emphasized the
inevitability of the theoretical inferences, "the importance for
theory", as he said, of the new direction of the investigations. Their
realization has actually enriched science, at the very least, in a
number of respects. We would like to dwell on only two problems, both
of fundamental importance .
28l
"Active" injection into the stratosphere in that year and into
cosmic space in our day assumes the flight of a man-investigator, a
scientist. For precisely this reason the condition of the higher ner-
vous activity of the astronaut attracts special attention. Among the
various problems faced by physiologists the study of the analyzing
function acquires essential importance.
Study of the analyzing function is not infrequently carried out
in a one-sided way, separated from reality. The characteristic feature
of the environmental conditions, the analysis of which is carried out
in man, is the synthetic character of the actual stimuli, their spatial
and temporal stereotypia. This was shown with complete precision by
I. P. Pavlov and his students as they studied the synthetic conditional
reflexes and the phenomena of the dynamic stereotype (P. S. Kupalov,
E. A. Asratyan, G. V. Skipin, L. G. Voronin and others). L. A. Orbeli
proposed the term "interaction of afferent systems", especially for the
phenomena exhibited by this physiological mechanism which had been dis-
covered by analysis of human sensations .
This subject, which was studied for many years in his laboratory
and the laboratories of other research scientists (S. V. Kravkov, G. Kh.
Kekcheyev and others), was shown to be of decisive importance in cosmic
physiology. The effect of overwork involving the specialized and gen-
eralized proprioceptive afferent systems, the skin and interoceptive
analyzers, the condition of weightlessness--all these form an unusual
ensemble of stimulation, conditions of interaction of the afferent sys-
tems which are new in comparison with terrestrial conditions.
A more serious reorganization occurs which is summed up as the
result of the individual experience of the system of analyzer interac-
tion. In practice, this problem has not been adequately studied, al-
though some attempts to study interaction within the limits of the
vestibular analyzer were begun by V. I. Voyachek and K. L. Khilovym and
continued by Yu. G. Grigor'ev and his coauthors with the application of
modern methods . The work showed from the start the complexity of the
physiological mechanisms of interaction of the visual and vestibular
analyzers (E. Sh. Ayrapetyants, V. A. Kislyakov, our findings).
L. A. Orbeli drew attention of future research workers to the
characteristics of the environment in which the crew of the strato-
spheric craft exist. He spoke first of our then inadequate information
about the biological role of an entire series of environmental factors,
in particular of those effects on man which cosmic rays might have.
Orbeli did not raise the problem casually. In his time, when he per-
sonally assisted in the experiments of Zvaardemaker, Orbeli became
interested in radiological problems. Many years later he entrusted
T. K. Dzharak'yan and me to repeat these experiments and organized in
the postwar years a special laboratory for the study of the effect of
282
ionizing radiation on biological specimens . Studies at the present time
have shown sufficiently well the possible effects of radiation on the
astronaut organism and have measured the actual dose which our first
discoverers of the cosmos sustain.
The question of the effect of these small doses of ionizing radiation
on the organism is gaining special interest in connection with the total
problem of the effect of the environment on the human organism. This
problem has been well studied under the conditions of living things on
our planet. However, conditions in the cosmos compel a review of the
many opposing conditions and an evaluation of a number of features
from a new point of view.
Actually the disturbance in the interaction of the afferent sys-
tems- -inevitable in cosmic flight --probably can be compensated by the
formation of new coordinated associations with the sensory sphere. The
development of stereotypes under these conditions lies within the limits
of the adaptive capacities of the organism.
But there are other factors in this newly conquered living environ-
ment, one of which is ionizing radiation. It is possible that adapta-
tional, adjustive mechanisms against the action of these factors exist
if the dose of radiation obtained in the cosmos exceeds the natural level
of radiation on our planet and this radiation differs in its physical
character from the natural background radiation.
This question is quite complex. At the present time large amounts
of factual material have been collected which characterize the radio-
sensitivity of living specimens not only to "earthly" forms of radiation
but also, for example, to high energy protons, in connection with some
of the components of primary cosmic radiation. Some generalizations
have been made which emphasize the many existing features of the bio-
logical effect of radiation, as a factor of the living environment, on
the planet earth and in cosmic space (A. V. Lebedinskiy and Yu. G.
Nefedov) . All of this taken together requires that especially active
reference be made to the development of the problem, again that intro-
duced by Academician L. A. Orbeli, concerning the possibility of pro-
ducing an increase in the resistance of the organism to the effects of
radiation (1955)-
We now know that the peculiarities of the living environment are
not limited only to changes in the condition of the effect of the gravi-
tational field, to an increase in the natural level of radiation. It is
necessary, evidently, to take into account the effect of a factor such
as the electromagnetic radiation of the planets.
This problem also disturbed Orbeli. Different facets of the prob-
lem evoked interest; such as man in extreme environmental conditions.
283
He was an initiator at that time, and, with the physicists M. A. Bonch-
Bruyevich and M. M. Shuleykin, he was a consultant for a great series of
experiments "by his coworkers on the problem of the effects of electro-
magnetic oscillations on the organism and especially on the nervous
system. This research was the first modern work on the study of the
effects of metric and centimeter waves on the nervous system, the re-
sults of which leave no doubt of the biological activity of this factor.
The research worker of our time recalls with appreciation the ear-
lier workers in his field who have bequeathed to him facts, reflection
on which advances him toward the discovery of new and unknown things
in science. A completely special feeling arises in relation to the
scientist who thought of the worker of the future and paved the way for
his research. L. A. Orbeli belongs to this group of scientists. And
now, after man's conquest of cosmic space, we must not forget his in-
terest in the problem of life beyond the earth, which was then only
contemplated in its murky contours . He actively penetrated into the
future, into a science which is now the science of our time, and brought
us closer to the solution of the most important problems of natural
science.
I
mi in mini ii mi
28U
SOME PHYSIOLOGICAL ASPECTS OF THE SYSTEM OF ASTRONAUT
SELECTION AND TRAINING
(Based on an evaluation of the functional condition of the
vestibular analyzer)
A. V. Lebedinskiy, N. I. Arlashchenko, B. B. Bokhov,
Yu. G. Grigor'yev, L. N. Kvasnikova and Yu. V. Farber
The problem of a physiologically substantiated system of selecting
pilots and astronauts now looms very high, in view of the increasingly
complex conditions of flying in modern aviation facilities and the
practical realization of manned space flights in our country. One of
the most important features of such a selection system is the investi-
gation of the functional condition of the analyzer of the body position
and movements in space (V. I. Voyachek, K. L. Khilov, G. G. Kulikovskiy,
etc. ) .
The evaluation of the analyzer as a complicated system formed in a
process of evolution should be one of the basic physiological principles
underlying the development of a selection system. The required infor-
mation is produced by a number of analyzers (vestibular instrument and
visual analyzer), the retina, and eye-muscle apparatus (motor analyzer
and, in a number of cases, interoceptive analyzer). The fact that an
analysis of the position and movements of the human body is to a large
extent formed in the process of ontogenesis leaves no doubt that the
mentioned process is realized by conditioned reflex mechanisms of various
complexity (synthetic and chain conditioned reflexes, stereotypy, etc.).
The performance of every analyzer is generally accompanied by
vegetative reactions, which can be particularly pronounced under certain
conditions of the functions of the analyzer of the body position and
movements in space. This may be a matter of great practical importance,
reflecting undesirable complications in space flight. Experience shows
that one cause of a vegetative reaction might be the failure of informa-
tion on the position and movements of the body, resulting in derangement
of the stereotype developed in the course of experience (the disruption
of the interrelation between the afferent systems in the conditions of
space flight).
In addition to a thorough and differentiated investigation of each
of the components of the analyzer system, these considerations call for
a study of (a) the interaction of these components and (b) the condition
of the vegetative functions in the case of unusual conditions of analyzer
interaction (space flight conditions).
The unusual conditions of analyzer functioning in space flight imply:
(a) a limitation of the information customary in terrestrial conditions
285
resulting in the derangement of the stereotype, and (2) the inclusion of
additional stimulants in this background (vibration, noise, etc.). More-
over all this may take place against the background of a changed func-
tional condition of the vestibular analyzer (especially its higher sec-
tions) under the affect of ionizing radiation (Yu. G. Grigor 'yev, A. V.
Moskovskaya, V. V. Petelina, A. A. Sveshnikov, A. V. Sevan 'kayev, etc.).
Complications disrupting the normal functioning of the cortical mechan-
anisms, as a result of the changing cerebral blood circulation (R. M.
Gerasimova), are also possible in extreme conditions.
A Differential Study of the Functional Condition of a
Vestibular Analyzer
The data on a differential investigation of the vestibular analyzer
will be outlined in this report, and some information on the interaction
between the receptor formations of the nonauditory labyrinth will be
cited. It should be emphasized that the vestibular analyzer is considered
as a complicated system with possible interaction phenomena within it.
Still not available is an adequate system of differential investi-
gations of various receptor systems of the nonauditory labyrinth even
though all the prerequisites are available for that purpose : an otolithic
reaction (V. I. Voyachek) for the study of the interaction of the otoliths
and semicircular canals; a four-pole swing test (K. L. Kbilov) for the
study of the otolithic function; and, finally, various modifications of
rotary tests (Barani, Bais-Fisher, Egraond, etc.) to stimulate the semi-
circular canals.
In each individual case, the investigation calls for a strict ob-
servance of the conditions required by the adequacy of the stimulus and,
in this connection, its accurate quantitative evaluation. These re-
quirements are satisfied by rotary devices (A. Kh. Minkovskiy, Hollpike,
Flur, etc., etc.) designed for the exclusive investigation of the semi-
circular canal functions by the use of preset magnitudes of angular
accelerations and velocities.
The experience in operating the new VU-2 installation (Yu. G.
Grigor 'yev and B. B. Bokhov), contained in an analysis of the published
information as well as in the data produced by the authors themselves,
revealed the practicality of investigating the functions of a vestibular
analyzer in these directions :
(1) Determining the threshold sensitivity of the semicircular canals
to an adequate stimulus.
(2) Determining the reactivity curve produced by the use of angular
accelerations of various magnitude.
286
(3) Evaluating the adaptivity to the effect of angular accelerations.
(1^-) Testing, utilizing Coriolis acceleration whose final reaction
apparently results from the stimulation of various receptor formations
of the nonauditory labyrinth.
Threshold Sensitivity
The method of determining the threshold sensitivity of the semicir-
cular canals to an adequate sximulus has until recently played an auxil-
iary part in the investigation of the function of the vestibular analyzer
(V. I. Voyachek, A. P. Popov, Voletts, etc.). This has been due to the
lack of an appropriate apparatus for the development of a standard series
of angular accelerations from test to test. There has been a growing
interest recently in the evaluation of the vestibular sensitivity in
clinical practice (V. I. Olisov, Montandon, etc.), where minimal angular
acceleration is used for determining the threshold sensitivity of people
suffering from various diseases (labyrinthitis, Meniere's disease, hyper-
tension, hearing disorder, and brain tumor). In a number of cases, a
low sensitivity that cannot be detected by the usual rotation can be
easily determined by the use of threshold tests.
The methods we used for determining the threshold sensitivity in-
clude the definition of the thresholds of both positive and negative
acceleration. The examinations of fairly healthy people (50 subjects)
revealed, first of all, that the fluctuation range of threshold sensitiv-
ity is small, within 0.1-0.5°/sec (acceleration effect lasting 20
seconds) to positive acceleration and 1.5-5°/sec2 (in 0.15 seconds) to
negative acceleration (stop-stimulus). But the results of special ex-
periments indicated that the threshold of vestibular sensitivity can
change several times under the effect of various stimulants and physical
factors of the external medium, including inadequate ones.
The available factual material justifies the belief that a study
of vestibular thresholds will be most useful in cases of early latent
disruptions of the analyzer activity which cannot be detected by other
means, and may be used for adapting the vestibular analyzer to various
conditions.
Reactivity Test
The most widespread and universally recognized method of investi-
gating the function of the semicircular canals consists of various
rotary tests (Barani, Voyachek, Beis-Fisher, Egmond, etc.). Such tests
amount to a study of the reactions occurring at the time of the deceler-
ation of the chair following a certain period of uniform rotation.
287
Obviously, the major methods to "be used in the future will be the method
of minimal stimuli (Beis, Fisher-Arslan, etc.) and the method of suc-
cessive rotations with an increasing intensity. The basic problem to
be solved is the selection and evaluation of an appropriate reaction in
order to characterize the functional state of the vestibular analyzer
under the effect of the growing intensity of the stimuli. Our observa-
tions of people show that vegetative reactions do not occur under the
effect of stimulants within the range indicated by the authors of
"cupulometry". And since the condition of the vestibulo-vegetative
complex is of decisive significance for an evaluation of suitability
for flying service (V. I. Voyachek, K. L. Khilov, etc.), it is obvious
that in order to establish distinct vegetative displacements we must use
the ones that lend themselves to a quantitative characterization. It is
also a known fact that the amplitude, duration, and speed of the nystag-
mic reaction are, as a rule, inadequate indices of the actual state of the
test subject's vestibular function.
Our own investigations justify our belief in the future use of a
method based on a longer duration of the effect of the stimulant rather
than on its increased strength, as well as on the evaluation of the
quantitative relationships among the magnitudes of the stimulants of
sensory, somatic, and vegetative reflex reactions.
It should be borne in mind that the latter are brought about by a
variety of mechanisms. The participation of the reticular formation in
the appropriate effects may be judged from the results of the following
tests. After the introduction of one mg/kg aminazine into rabbits, the
vegetative reactions to vestibular stimulation grow much weaker and even
disappear. Under these conditions, the reaction in the form of a nystag-
mus continues, or even grows more intense. These relationships continue
also after the exposure of the animals to ionizing radiation.
Vestibular Adaptation
Numerous experiments have shown that the training consisting of the
systematic irritation of the vestibular apparatus by various exercises
and rotary tests enhances the vestibular stability of the test subjects.
Here the speed of human adaptation depends on the particular individual.
This brings up the problem of developing a test for the objective eval-
uation of the degree of adaptation.
A successful attempt of this type was made by Egmond who recorded
the nystagmic reaction under the effect of repeated stimulants. But the
duration of the nystagmus is apparently an inconclusive indicator for
any definitive prognostic conclusions, as this would leave the vegeta-
tive complex out of account. This prompts the assumption that only an
overall evaluation of the vestibulo-vegetative, vestibulo-somatic, and
sensory reactions to repeated stimulants reveals the actual picture of
288
the adaptive characteristics of a vestibular analyzer. Relevant labora-
tory investigations ■ are currently under way.
Coriolis Acceleration
The purpose of using the Coriolis acceleration as a selection test
is to study the summary reaction, interaction, and mutual influence of
various labyrinth receptors to the stimulation produced by the combi-
nation of two vector magnitudes --angular and linear velocities. The
test is of special practical interest, as the possibility of a Coriolis
force emerging during the flight is very real.
Laboratory investigations involving the periodic effect of Coriolis
acceleration against the background of a slow rotation revealed that even
a short-lived rotation is conducive to a pronounced disruption of the
gait and changes in skin temperature and pulse frequency. As for the
vestibular analyzer, it revealed a lower threshold sensitivity to Coriolis
acceleration with the thresholds of angular acceleration remaining un-
changed. Thus, the first results showed that such investigations had a
promising future.
Interaction in the System of the Analyzer of the Body
Position and Movements
The most interesting feature of these investigations was the study
of the interaction between the optical and vestibular analyzers begun
by G-. Ye. Zhukov in I. P. Pavlov's laboratory. The resulting experi-
mental data are, as a rule, indicative of the inhibiting effect of the
retina on the vestibular analyzer. This phenomenon has been confirmed
by the experiments in our laboratory involving the use of precise methods
of evaluating the reactivity of the vestibular analyzer, and taking into
account the intensity and duration of a luminous stimulant.
It appears that the result of the interaction between a luminous and
vestibular stimulant is determined by the functional condition of the
vestibular analyzer. The tests have revealed that when the excitability
of the vestibular analyzer is increased and a spontaneous nystagmus ap-
pears, the latter is clearly inhibited under the effect of the luminous
stimulation of the retina. The excitability in these experiments was
increased by placing an applicator in the perilymphatic space of the inner
ear vestibule. As proposed by A. B. Malinin, the applicator (a ball
consisting of ion-exchange resins and measuring about 1 mm in diameter)
was saturated with a radioactive promethium isotope Prl^7. The Prl^7
is characterized by a beta-radiation of a very low energy (0.22 kev),
which makes it possible to use this isotope to produce local damages on
the microscopic structures. The capacity of the source on its surface
289
amounted to 6. 17 -10 3 radian/hour. At a distance of 250 microns, equal
to the thickness of the sensitive layer of the utricular macula, the
radiation intensity amounted to h& radian/hour.
After 2k hours, the continuous effect of the ionizing radiation on
the sensitive concretions of the ear labyrinth, recorded in the dark by
an oculogram, revealed the presence of a "spontaneous" nystagmus in the
animal. The effect of the light resulted in the immediate cessation of
the "spontaneous" nystagmoid movements of the eyes. In the following
days, as the excitability of the vestibular instrument was further in-
creased, the inhibiting effect of the light became less pronounced.
THE PROLONGED EFFECT OF SLOW CORIOLIS ACCELERATIONS
ON THE HUMAN ORGANISM
A. V. Lebedinskiy, N. I. Arlashchenko, V. Ye. Busygin,
R. A. Vartbaronov, A. S. Veselov, N. A. Volokhova,
Yu. G. Grigor'yev, M. D. Yemel 'yanov, T. V. Kalyayeva,
Yu. V. Krylov, B. I. Polyakov and Yu. V. Farber
A prolonged stimulation of the vestibular analyzer produced a so-
called airsickness syndrome (V. I. Voyachek, K. L. Khilov, A. P. Popov,
Witt, Schubert, Graybil, etc.). These reactions are determined by the
functional changes in the nervous system and, possibly, by the disruption
of the humoral control mechanisms. There are very few publications on
the nature of the developing reactions to a prolonged stimulation of the
vestibular analyzer by slow Coriolis accelerations (S. F. Stein, S. G.
Chebanov, Graybil, Clark, Zariello, etc.). At the same time, the
astronaut's tolerance of the Coriolis acceleration in orbital flight
conditions is now a matter of great practical importance. A scientific
substantiation of the magnitude of artificial gravitation produced in
spacecraft calls for a physiological investigation into the protracted
effect of the Coriolis acceleration on the human organism.
Coriolis acceleration effects on the human organism have been studied
in a slowly rotating chamber (MVK-l), a Soviet-made installation for the
investigation of the organism's reactions to the prolonged effect of
slow Coriolis acceleration.
The MVK-l is a closed cylindrical chamber measuring 2.1 meters in
diameter and 2.3 meters in height. Its equipment consists of two armchairs
for the test subjects, an electric light and ventilation system and a
290
device for the continuous recording of the physiological functions during
the rotation.
Thirteen healthy persons participated in the first series of ex-
periments, in which the chamber was rotated 1-5 hours at a constant
angular speed of 5.3°/sec. The second series of experiments (which was
carried out jointly with R. A. Vartbaronov and Yu. V. Krylov and in
which the chamber was rotated for 2k hours at constant angular rotation
speeds of 5-3, 10.6 and 21.2°/sec) involved the use of four test sub-
jects. A Coriolis acceleration was produced periodically by tilting
the body and head in planes perpendicular to that of the stand rotation
at the rate of one movement per second. In the control investigations
(remaining in the chamber when it was not rotating), the test subjects
observed all the experimental conditions.
The general condition and neurological state of the test subjects
were examined, their coordination of movements was tested, the thermo-
regulation function was evaluated, and the peripheral^blood was in-
vestigated before and after the rotation. The functional condition of
the vestibular analyzer of the test subjects was studied in a VU-2 device
(Yu. G. Grigor'yev and B. B. Bokhov (1961)) for the sensory (a feeling of
counterrotation), somatic (nystagmus), and vegetative (maximum arterial
pressure, the propagation speed of the pulse wave, the pulse and res-
piration frequency) components of the vestibular reaction to stimulations
under threshold and superthreshold conditions. Observations were made
during the rotation of the microclimate in the chamber; thermoregulation
of the test subjects was studied, and the functional condition of the
cardiovascular system, respiration, and auditory analyzer was determined,
as were the working capacity of the test subjects and the condition of
their peripheral blood.
The periodic effect of the Coriolis acceleration on the test subject
kept in an MVK-1 (at a speed of 5.3°/sec) for 1 hour and 5 hours revealed
no considerable functional disruptions. The subjective phenomena occur-
ring in a few of the test subjects under the operating load appeared in
the form of mild dizziness, a feeling of heaviness in the head, and
unpleasant sensations in the epigastric region. There were changes in
the skin temperature and more pronounced disruptions in the coordina-
tion of movements (there were twice as many errors in the exercises
involving "a complicated walk").
A further increase in the speed (up to 21°/sec) and duration (up to
2h hours) of the chamber rotation resulted in more pronounced phenomena,
particularly in persons with a low vestibular stability. Increased
somnolence and apathy as well as a reduced mental and physical capacity
were noted. After several (l-5) hours in the MVK-1 chamber, the above-
mentioned disturbances were considerably alleviated, and the general
feeling of the test subjects was improved, probably through adaptation to
291
the effect of Coriolis acceleration. The required adaptation period in
this case was prolonged in proportion to the increasing rotation speed,
(it should be pointed out that in one case of a 21.2°/sec rotation speed,
a test subject with a low vestibular stability revealed no adaptation
at all.)
In most of the test subjects the body temperature in the course of
rotation was reduced by 0.2-0.8°C; in one of the subjects with a high
vestibular stability it systematically went up 0.5-1.0°C. In addition,
a rotation speed of 10.6-21.2°/sec produced characteristic changes in
the skin temperature of the wrist (an average increase of 1.5-3°C) and
shin (an average drop of 1.5-^. 5°C in the first hours of the test)
areas .
An investigation of the cardiovascular system revealed a consider-
able strain with an occasional distortion of the pulse reaction; a con-
siderable reduction of the diastolic wave on the seismocardiogram, as
shown by ortho- and spheno-static tests; and a considerable fluctuation
of the duration of the mechanical and electrical cardiac systoles.
The changes of the morphological composition of the blood at all
rotation speeds were of a reactive nature associated with the redistri-
bution of the positive elements.
An investigation of the auditory function showed a drop of the
auditory sensitivity in the middle of the test by 10-25 decibels at a
rotation speed of 10.6-21.2°/sec. An examination of the simple sensori-
motor reaction to sound and light revealed an increase in the latent re-
action period in the first hours of rotation at a speed of 21.2°/sec.
An upset body equilibrium, as indicated by a staggering walk which
was particularly pronounced when the eyes were closed, was noted im-
mediately after the rotation in an MVK-1 chamber.
In the first 2-3 days after the experiment, all the test subjects
complained of headaches, nausea and disturbed sleep. The reactivity of
the vestibular apparatus to angular accelerations in the aftereffect
period remained unchanged. On the other hand, there was a tendency to
a reduced sensitivity to a Coriolis acceleration and a reduction of the
vegetative manifestations produced by the otolithic reaction in all the
test subjects.
The above-mentioned observations justify the assumption that the
main reason for the development of vestibular disturbances during a slow
rotation is the combined stimulation by the slow Coriolis accelerations
of the otolithic apparatus and the semicircular canals; this is con-
ducive to a summation of the afferent impulses. The lengthy afferent
flow from a vestibular receptor of an unusual nature accounts for the
inclusion of a number of neurohumoral mechanisms (stress reaction is one
292
of their possible manifestations). If the force of the vestibular stimu-
lation does not exceed the tolerance level, it may lead to development
of an adaptation.
Conclusions
1. The lengthy rotation of the test subjects with a normal ves-
tibular sensitivity at speeds of 5.3, 10.6, and 21.2°/sec produces
functional changes in the CNS and the cardiovascular system, and a dis-
ruption of the thermoregulation and the equilibrium function.
2. The extent of the vegetative disruptions is directly related
to the rotation speed and the degree of vestibular sensitivity of the
test subjects.
3. The cumulative effect of the Coriolis acceleration on most of
the test subjects was conducive to a state of adaptation which was noted
1-5 hours after the beginning of the rotation.
h. The threshold and maximum tolerable Coriolis accelerations with
reference to the conditions of the experiment we selected have been
established.
5. The mentioned investigations justify the recommendation of a
lengthy slow rotation for purposes of laryngo-oto-rhinological expertise
and training.
LABOB HYGIENE AND OCCUPATIONAL PATHOLOGY INVOLVED IN THE
WORK WITH CENTIMETER WAVE GENERATORS IN THE CIVIL AIR FLEET
A. Ya. Loshak
The development of new aviation facilities and the constantly
growing traffic of airborne passengers and freight call for a continu-
ous improvement of the flight safety systems. The radar stations (RS)
play an important part in this effort.
The service personnel engaged in the operation and repair of these
installations are subject to exposure to UHF electromagnetic energy and
a number of other unpleasant factors (discomforting microclimatic con-
ditions, noise, soft X-ray radiation, etc.).
293
Most of the information available in Soviet and foreign literature
on the characteristic features of the radar station operations (N. F.
Galanin and coauthors, N. I. Matuzov, A. I. Senkevich, V. A. Spasskiy,
N. V. Tyagin, Khadukh, etc.; Khauf and Zatichelli, etc.) characterizes the
conditions of the operators ' work and not of the engineering and technical
personnel. The latter groups have a more continuous and closer contact
with radiation. Moreover, almost all of the mentioned publications con-
tain a very detailed description of the general hygienic factors and
only a reference to the harmful specific effect of the UHF field, and
they do not provide a quantitative evaluation of that factor even though
it is the radiation dose that is primarily responsible for the pathogenic
effect of the microwaves.
In addition to providing a hygienic evaluation of the entire complex
of injurious factors observable in the operation of a radar station,
this report focuses major attention on the causes of UHF-radiation of
the engineering-technical personnel of a radar station, as well as the
intensity and duration of this effect in the course of a working day.
Our information reveals that radar service crews are systematically
exposed to UHF energy which originates primarily in the antennas and,
to a lesser extent, in the r-f units and waveguides (if they are inade-
quately shielded or not closely coupled). In such cases, radiation may
be emitted from several sources simultaneously. The radiation intensity
fluctuates from units of microwatt/cm2 to several thousand microwatt/cm2,
and is determined by the type of radar station, the conditions of its
operation and the observance of the safety regulativ ns .
The duration of the radiation during a working day, in addition to
the above-mentioned causes, depends also on the conditions of work, and
the nature of the repair and routine operations, which may last one to
several hours .
The most significant factors determining the intensity of the ir-
radiation of people, according to our information, include: (a) the type
of station, (b) the height of the installation and the operating tilt
angle of the antenna, (c) the distance to the antennas and (d) the local
topography.
The data on the flux density of the UHF energy (depending on the
distance to the antennas, the height of the installation and their tilt
angle) produced in the operation of various types of radar stations
have been arranged in special tables.
The measurements made by our own methods reveal an inverse relation-
ship between the intensity of the UHF-radiation at the place of the
measurement and the height of the installation as well as the tilt angle
of the antennas. These data show also that the adjacent territory is
29^
subjected to periodic radiation of a great intensity when the antenna
areas are characterized by a low elevation and negative angle.
The biological significance of periodic radiation has not been
adequately studied even though the urgency of this problem is obvious.
The tendency to increase the permissible levels of periodic radiation
should be carefully substantiated and should not, it seems to us, be
applied to the radar station personnel who are frequently exposed to
continuous rather than periodic radiation with varying intensity. This
is all the more reason why we should not accept the definition of the
actual radiation time (and this implies also the permissible radiation
level) on the basis of the rotation periodicity or the antenna scanning
and the width of the beam.
With respect to the manifestations of the chronic effect of the
UHF field on the radar station personnel, the literature shows no un-
animity of opinion. While some of the authors believe that the ob-
servable changes in the health of the radar workers are due to the
violations of the general hygienic conditions of work and overfatigue
(M. S. Kagan, V. D. Lindenbraten, Barron and coauthors), many Soviet
and foreign researchers attribute such changes to the specific effect
of microwaves (G. A. Krivkov, N. V. Tyagin, Berest, etc.; Edel 'vayn,
Koritovskiy, etc.; Manezarskiy, Marek, Serel, etc.).
A clinico-physiological examination of radar station personnel and
the compilation of medical documentation revealed a number of cases of
complaints and objective information characteristic of an astheno-
vegetative syndrome specific to the chronic effect of UHF energy. It
was noted that the number of complaints and the nature of the changes
increase with the length of service, most frequently among the service
personnel operating the radar facilities within 10-centimeter and de-
cimeter ranges. The frequency and depth of the changes are also affected
to a large extent by climatic conditions — the changes recorded in the
southern latitudes were more frequent than in the central and northern
latitudes.
The investigations made into the higher nervous activity and
fatigability justify the assumption of some predominance of inhibiting
processes in the contingent under study which, according to M. S. Bychkov,
also indicates a pronounced asthenic process in them.
A study of the working characteristics -t the radar stations has
made it possible to propose a number of recommendations to improve the
sanitary conditions of the service personnel for the express purpose of
reducing the UHF radiation. These recommendations provide for the most
rational principles governing the arrangement of the equipment and the
planning of the radar sites, from a sanitary point of view; for design
changes in the shielding system at certain radar stations; and for a
295
number of organizational measures, including the establishment of speci-
fied sanitary safety zones. The establishment of the latter will be
based on the measured radiation emitted by the different radar antennas,
and not on any calculation, inasmuch as such calculations do not pro-
duce any satisfactory results.
The constantly expanding use of radar stations in the civil air
fleet, the expected introduction of new wave bands, the increasing
capacity of the transmitters, and preferential use of antennas producing
high directional radiation beams, as well as the current safety meas-
ures at the radar stations require the medical worker to make a sys-
tematic study of the labor conditions and the health of the people
operating these installations .
Conclusions
1. The engineering and technical personnel of the radar stations
of the civil air fleet are systematically exposed to direct and scattered
UHF-radiation of varying intensity, from single units to several hundred
(precision approach and dispatcher radar stations) and thousands of
microwatt/cm (circular scanning stations).
2. An examination of the personnel revealed in some of them
symptoms of functional astheno- vegetative disruptions, the frequency
and extent of which are determined by the length of service, the type of
station, the shielding system, and climatic conditions.
3. The prevention of the injurious effect of the microwaves on the
radar service personnel should be based primarily on organization and
planning measures, followed by the use of protective devices.
h. A number of measures have been proposed to prevent the effect
of the UHF-f ield on the radar station personnel : sanitary safety zones
for different types of stations, new principles of planning and dis-
tributing radar facilities, some design changes in the shielding system,
as well as new methods of dosimetric measurements and sanitary investi-
gation of the radar facilities.
5. The data on sanitary-dosimetric and clinico-physiological in-
vestigations emphasize the necessity for a regular control over the
conditions of work and health of radar station personnel.
296
THE VIBRATION AND RADIATION EFFECT ON THE ACIDIFYING
PROCESSES IN THE BRAIN TISSUES OF RATS
L . D . Luk ' yanova
One of the important factors of space flight is vibration, which
produces a large variety of functional disturbances in the animal and
human organisms. There are indications in the literature that one of
such disturbances is an increasing consumption of oxygen in proportion
to the vibration frequency and amplitude. Bearing in mind that the
rate of oxygen consumption by the brain is very high, and that the
continuous supply of oxygen to the brain is an indispensable condition
of its normal activity, the great importance of studying the acidifying
processes in the brain tissues becomes obvious.
This project involved an investigation of one of the major factors
characterizing the oxidation rate in the cell, and the partial oxygen
pressure or tension (pOo) in various sections of the brain.
The pOp was measured by the "oxygen cathode" method, which is based
on the principle of polarographic analysis. A platinum electrode was im-
planted in the animal's brain, and a chloro-silver nonpolarizable elec-
trode introduced subcutaneously . Feeding negative electricity to the
platinum electrode of the lobes produced an electrolytic oxygen reduction
in the solution which generated a current proportional to the oxygen
concentration that could be measured.
It was shown that the vertical vibration of the animals (frequency 70
hertz, amplitude O.k mm, duration of effect 15 minutes) produces very
regular changes in the consumption of oxygen by the brain tissues. The
consumption of oxygen, beginning with the first effect, is sharply
increased. The vibration is followed by an undulating development of
an inhibition process characterized by a reduced consumption of oxygen by
the brain tissues, and lasting two hours. The following hours reveal a
normalization of the process.
In animals subjected to repeated vibrations (up to 10 times), the
brain consumption rate of oxygen during the vibration increases faster,
and diminishes more slowly, than in animals subjected to vibration only
once. However, there are periods of apparent normalization. Some in-
crease has been noted in the total oxygen content of the brain tissue
at the end of the vibration and for some time after it.
The changes in oxygen consumption rates in the different regions
of the brain under the effect of vibration are expressed in different
ways. These are most conspicuous in the motor region of the cerebral
cortex. Irradiated animals (minimum lethal dose 600 radians) revealed a
297
decreased oxygen consumption immediately after their exposure, but such
consumption was back to normal 1-2 days later. However, an investiga-
tion of the pO changes in the brain tissues of the animals subjected
to a combined effect (vibration followed by irradiation) revealed a
predominance of the vibration effect.
The reaction of various animals to the effects under investigation
was qualitatively similar, but its duration and intensity were largely
determined by the individual characteristics of the animals.
AN ELECTROENCEPHALOGRAM OF AN ACUTE HYPOXIC (sic) HYPOXIA
V. B. Malkin
We have studied the bioelectric brain activity in fairly healthy
young people in various stages of hypoxia for a long period of time.
The electroencephalograms (EEGs) were accompanied by electrocardiograms
(EKGs), a recording of the respiratory movements, arterial blood pres-
sure, and a determination of the oxygen- saturation of the arterial
blood. The EEG was accompanied by a psychophysiological examination,
including a study of the rate of simple conditioned motor reactions,
the recording of a well-memorized text, the solution of simple arith-
metical problems, as well as a recording of the general feeling.
The purpose of the investigation was to determine the diagnostic
significance of the various changes on the EEG in the process of estab-
lishing the test subject's individual resistance to hypoxia, as well as
a study of certain aspects of the physiological mechanism which deter-
mines the various forms of EEG changes in cases of oxygen insufficiency.
Animal experiments have sought a solution to the latter problem.
Some test subjects raised in a pressure chamber to an altitude of
5,000 meters felt quite satisfactory after 3O minutes at that altitude,
but a psychophysiological examination revealed a significant disruption
of the functional state of the CNS, as could be gleaned from the loss of
certain practices acquired in the process of education: these included
such grammatical mistakes as the omission of latent sounds, the mis-
spelling of words with unaccented vowels, etc. A visual as well as a
spectral analysis of the EEG, accompanied by a determination of the bio-
electric intensity of the various parts of the spectrum, failed to detect
any deviations from the norm.
298
It has been established that the initial symptoms of a disrupted
activity of the CNS in conditions of a moderate hypoxia can occur while
the EEG remains within the norm.
A study of the EEG changes produced by the development of hypoxia
at altitudes of 6,000-7,000 meters has established that in the initial
phase of hypoxia during the development of compensatory reactions on
the part of the respiratory and cardiovascular organs, the EEG as a
rule reveals an activated p-rhythm. The activation of the a-rhythm,
which Kornmueller, etc., believed to be the initial phase of EEG changes,
has, according to our information, been noted in less than 50 percent
of the investigations, and it occurred after the activation of the p-
rhythm.
In some cases, the various EEG phase changes, in point of time,
were not strictly defined so that one phase appeared to be running into
another as it were: (the p-activation phase into the a-rhythm activation
phase or the 0-wave phase).
The predominance of 9 waves on the EEG coincided with the manifes-
tation of visible disruptions of the activity of the CNS--a frozen pose--
initial distortions of the handwriting, and insignificant increase in
the latent periods of conditioned motor reactions. It has been estab-
lished that the ©-rhythm domination phase on the EEG, and in some cases
also the A-phase, can be divided into two phases : a phase of a stable
9- or A-rhythm, when the external stimulation and the performance of
various assignments by the test subject do not produce substantial EEG
changes, and a phase of unstable 9- or A-rhythm, when the effect of
external stimulants or the performance of various tasks by the test
subject (recording his feeling, solving some problems, etc.) results in
the disappearance or sharp reduction of the number of 0- and A-wavcs,
and the activation of high-frequency oscillations on the EEG.
The EEG thus indicated a "waking" reaction as it were. It was shown
that the growing intensity of the bioelectric brain activity in the low-
frequency spectrum (2-6 hertz), which was more than double the stand-
ard norm, usually indicates incipient functional disturbances of the
CNS amounting to a certain reduction of working capacity. A further
intensification of the bioelectric activity in the low- frequency spec-
trum by 200- 3OO percent is indicative of profound disturbances of the
CNo, including the loss of consciousness.
Serious hypoxia conditions, crude distortions of the writing proc-
ess, and clonic spasms in the writing hand produced the same changes
on the EEG as the loss of consciousness. Thus the qualitative or quan-
titative indicators characterizing the loss of consciousness cannot be
ascertained on the basis of a visual analysis of the EEG or a spectral
analysis of it, including a calculation of the bioelectric intensity in
various regions of the spectrum.
299
The EEG did not indicate any predominance of slow oscillations in
cases of people with a low resistance to hypoxia whose sharp drop in
pulse frequency put them in a state of near collapse. In such cases the
EEG revealed a reduced biocurrent amplitude, the latter being accompanied
in individual cases by an increasing number of high-frequency oscillations;
after that, the EEG of some test subjects showed sluggish and slow oscil-
lations of a relatively low amplitude.
A very essential feature of these experiments, conducted against the
background of a flattening EEG curve and a 3-rhythm activation, is that
the test subjects revealed external symptoms of a developing cortical in-
hibition: torpidity, a frozen pose, a longer latent period of motor re-
actions, etc.
Thus the predominance of slow waves is not the only form of EEG
changes produced by the development of profound hypoxia- connected dis-
turbances of the CNS. In this case, cortical inhibitions may be mani-
fested as a result of the predominance of high amplitude slow oscilla-
tions on the EEG, as well as a flattening of the curve and the activation
of the 3-rhythm.
The EEG data justify the assumption of the existence of two physio-
logical mechanisms disrupting the activity of the CNS : (a) the develop-
ment of an inhibition process, in the case of predominant slow oscilla-
tions on the EEG, as a result of the direct effect of the oxygen shortage
on the neurons of the cerebral cortex; (b) the disruptions of the ac-
tivity of the CNS against the background of developing vegetative
disturbances and lower biocurrent amplitudes on the EEG are probably de-
termined by the inductive inhibition effect on the cortex coming from
the subcortex whose irritability shows a sharp increase.
Investigations of animals suffering from acute hypoxia revealed
changes in the EEG beginning with the appearance of the first barely
noticeable disruptions of the CNS and leading to the development of
clinical death. During the development of hypoxia, all the test animals
regardless of species (dogs, cats, rabbits, or rats) produced phase
changes in the EEG. They were manifested in the successive alternation
of activated high-frequency oscillations (desynchronization phase),
and activated slow oscillations (hyper synchronization phase). The de-
pression of the biocurrents was the concluding phase of the EEG change.
It manifested itself in the gradual reduction of the biocurrent amplitude,
in the appearance of "complete silence" periods and individual spurts,
or discharges, coinciding with the rare terminal respiratory movements.
A definite correlation between the clinical picture of the develop-
ing hypoxia and the EEG changes was established when the animals were
raised in a pressure chamber to altitudes of 1,200-6,000 m at speeds of
25-100 m/sec. The activation of the 3 rhythm coincided with the initial
300
stage of compensatory reactions on the part of the respiration and blood
circulation. The predominance of high-amplitude slow oscillations in
the EEG coincided with the genesis of chronic spasms and the sharp re-
duction in the frequency of heart contractions. A fading bioelectric
activity was noted simultaneously with the appearance of profound dis-
turbances of the CWS: the loss of a normal posture, the disappearance
of conjunctival reflexes, the loss of the pain sensation, and a dis-
turbance of rhythmic respiration.
The experiments in which the test animals revealed an extremely
rapid increase in hypoxia in the first 1-2 seconds at an altitude of
15,000-16,000 meters showed that the correlation between the EEG changes
and the clinical picture of the state of hypoxia is determined by the
growing rate of hypoxemia. There was no p-rhythm activation phase in
these experiments, and the chronic spasms frequently coincided with the
depression of bioelectric activity.
The experiments involving repeated ascents of the test animals to
great altitudes revealed (in the second and third ascents) a lack of a
hypersynchronization phase so that the depression of the bioelectric
activity was not preceded by the domination of slow oscillations in the
EEG. It has thus been shown that individual EEG phases may be absent
in certain cases of developing acute hypoxia.
Investigations have been undertaken jointly with N. A. Asyamolova,
Yu. V. Izosimov and K. K. Monakhov with a view to studying the mechan-
ism governing the development of the phase changes in the EEG; these ex-
periments involved the cutting of the brain, in one series of test ani-
mals, above the frontal tubers of the lamina quadrigemina, and the iso-
lation of the cerebral cortex stria, in another series of animals in
order to eliminate the effect of the incoming afferentation of the
cortex and establish the direct effect of the oxygen shortage.
The development of acute hypoxia in the animals of the first series
was not indicated in the desynchronization phase of the EEG, which con-
firms the previous investigations by Dela and Bonvale. Despite the
separation of the cortex and the nearest subcortex from the lower brain
formations during the development of hypoxemia, there was an indication
of developing chronic spasms which were of shorter duration and less
intensive than in the intact animals. Thus the functional preservation
of the cortex does not determine the mechanism governing the development
of chronic spasms in cases of hypoxia, as has previously been indicated
by certain researchers (V. V. Strel'tsov, N. A. Nechayev, etc.).
The tests involving the isolation of the cortical stria revealed an
intensified discharge activity during the ascent to altitudes of K, 000-
10,000 meters and the development of hypoxia. This justifies the as-
sumption that the hypersynchronization phase of hypoxia may be produced
by the humoral effect of the oxygen shortage in the blood on the neurons
of the cerebral cortex.
301
An investigation of the electric excitability of the stria at alti-
tudes of 3,000-10,000 meters revealed a lower threshold of the induced
potential. At altitudes of 10,000 meters and higher, the threshold
continued to rise intermittently. The threshold changes were not strictly
correlated with the desynchronization and hypersynchronization phase .
Thus the EEG information shows that the cerebral cortex is directly
affected by hypoxemia or the metabolites resulting from its development.
THE CHARACTERISTIC FEATURES OF THE CLINICAL COURSE AND THE
EXPERT'S OPINION OF FLIGHT PERSONNEL AFFLICTED WITH
STOMACH AND DUODENAL DISEASES
Ye. T. Malyshkin and B. L. Gel 'man
1. Of all the digestive illnesses, the chronic disease of the
gastro- duodenal section of the gastrointestinal tract is one of the most
frequent reasons for the disqualification of flight personnel, and the
second most frequent internal disease .
We have set ourselves the goal of studying the characteristic
features of the clinical course and expert opinion concerning flight
personnel afflicated with stomach and duodenal diseases. Eighty-eight
persons suffering from ulcers and 101 chronic gastritis patients have
been examined over a number of years in the therapy department.
In addition, we have obtained and processed the necessary informa-
tion on the case histories of 3IO persons, 12^ of whom had suffered from
ulcers and 186 from chronic gastritis.
2. A study of all the data obtained from the case histories, as
well as the information on examined persons, failed to reveal any obvious
direct connection between the stomach and duodenal diseases of our
patients and the effect of specific factors characteristic of the flying
profession, or the intensity and duration of flying.
3. In the general clinical picture of the disease, including the
chronic development as well as aggravated ulcers and chronic gastritis,
there is one point in common, and that is the benign course of the men-
tioned diseases.
h. An X-ray examination revealed, in many patients, an ulcerous
"niche" surrounded with an inflammatory torus, but there was not a single
instance of that niche reaching a considerable size. Not a single case
302
of penetrating ulcers was observed nor any crude cicatricial stomach
deformations .
An X-ray examination of all the patients after their treatment
failed to uncover a single ulcerous "niche", which is also indicative
of the relatively benign course of the disease.
5. An examination of the gastric secretion by the fractional method
following a cereal breakfast and the use of an M. G. Solov'yey fine
catheter with olive oil revealed that gastric secretions were disrupted
most frequently in patients suffering from duodenal ulcers.
The use of the above-mentioned methods of investigation was based
on the results of our investigations into the comparative characteris-
tics of the methods employed over a number of years in the examination
of gastric secretion (B. L. Gel 'man, G. P. Mikhaylovskiy, R. M. Basov
and P. M. Suvorov) . These showed that a cereal breakfast is the best
physiological stimulant of gastric secretion. The examination of the
secretory activity of the stomach gland by the use of Dr. M. G. Solov'yey 's
fine catheter with olive oil makes possible a continuous study of the
secretory function of the stomach (complex reflex neurochemical) with
the use of the same stimulant .
The dynamic observations of a number of patients examined a second
time revealed a continuing high level of acidity and secretion. We
find an explanation for this in Yu. I. Lazovskiy's experimental work,
which showed that an increased secretory function of the stomach glands,
brought about by the stimulation of the vagus nerve, leads to an in-
tensified regeneration and hyperplasia of the glandular apparatus,
especially in the pylorus zone.
6. A study of the characteristic features of the higher nervous
system by the method of conditioned motor reflexes, preceded by appro-
priate instructions, revealed pronounced differences in the cortical proc-
esses in both the stages of remission and aggravation of 111 of the
ulcer and chronic gastritis patients under study (G. P. Mikhaylovskiy) .
The greatest disruptions in the cortical processes in the form of a
disequilibrium and restricted mobility were found in the majority of
people suffering from chronic gastritis and ulcers in an aggravated stage.
In the case of the former, this was accompanied by a weakening of the
inhibition process; in the latter, by a weakening of the stimulation
process, indicated by a deeper disruption of the cortical processes.
Repeated examinations of the ulcer patients in the remission stage (as
compared to an aggravated stage) established a partial or complete
normalization of the cortical processes .
7. The method of individual approach has been widely used in medi-
cal examinations of flight personnel suffering from chronic stomach and
303
duodenal diseases. This method calls for a study of a complex of prob-
lems affecting the patient himself (the conditions and nature of his
work and diet, his actual working capacity, the rewarding aspect of his
job and its purposefulness) as well as the characteristic course of the
disease.
8. Patients suffering from chronic stomach and duodenal diseases
should be kept in flight service and, if possible, on the same types of
planes they have been accustomed to. The retraining of such patients even
under favorable conditions of the disease would be impractical, as the
retraining process eventually produces additional neuropsychic tension
which may affect the course of the disease and contribute to its aggra-
vation .
9. In view of the development of aviation technology and the asso-
ciated changes in the various functions of the human organism, particularly
the very pronounced disruptions of the functional activity of the gastro-
intestinal tract, the complex ^ "f ects produced on the human organism by
a number of modern flight fa ors call for a revision of expert medical
opinion on the persons suffering from chronic stomach and duodenal di-
seases. We do not consider it advisable in the future to make use of
any flight personnel discovered to be afflicted with stomach or duodenal
ulcers, as well as chronic gastritis with a pronounced painful syndrome
or a tendency to aggravation.
ON THE DIAGNOSIS AND EXPERT MEDICAL OPINION OF FLIGHT
PERSONNEL AFFLICTED WITH ATHEROSCLEROSIS
Ye. T. Malyshkin, N. A. Gol 'din and V. M. Tolstov
A historical review of the study of the pathogenesis, epidemiology,
and etiology of atherosclerosis emphasizes the complexity of the pathogenic
nature of that disease, its widespread occurrence among the population in
most countries and the increasing frequency and gravity of the disease
with advancing age.
Numerous researchers point to the widespread occurrence of athero-
sclerosis among flight personnel. In particular, in a histological ex-
amination of the myocardium of 222 pilots who died in aviation acci-
dents, V. Glents and V. Stembridge found, in 70 percent of cases, athero-
sclerotic changes in the wall of the coronary artery. In 21 percent of
the dead pilots, mostly between the ages of 30 and k0, the lumen had
been narrowed by the presence of atherosclerotic plaques . In three of
30^
the pilots whose flight had ended in disaster they diagnosed an acute
infarct myocardium.
According to 0. Koldovski, Novak and F. Vorel, pilots develop
atherosclerosis considerably earlier than people of other professions.
It is particularly difficult to diagnose the early occurrence of athero-
sclerisis because of the well-known fact in clinical practice that these
forms of atherosclerosis are, as a rule, asymptomatic and of an unde-
termined duration. Nevertheless, it is in this early stage that the
diagnosis of atherosclerosis is extremely important for its treatment
and prophylaxis .
We have made use of a number of complex clinico-physiological,
instrument and laboratory investigations for the purpose of diagnosing
the early forms of atherosclerosis. In addition to the usual general
clinical examination, this diagnostic complex pursued three major
purposes.
The first purpose of these investigations was to establish metabolic
changes; this was done by examining the protein fractions of blood serum
by the electrophoretic method; determining the cholesterol and its frac-
tions, the lecithin-cholesterol index, the lipoproteins; determining the
functions of the thyroid gland by the use of radioactive iodine-131,
the basal metabolism, and the penetrability of the vessels.
The second purpose was pursued by carrying out a complex of elec-
trophysiological examinations (EKG, ballistocardiogram (BKG) and vector-
cardiogram (VKG)), in a state of rest and after normal activity, as well
as under special work loads which are most characteristic of certain
types of the flying profession. Such workloads included a number of
hypoxic tests used under normal and reduced barometric pressure, as well
as by the method of breathing an oxygen-poor gas mixture under excessive
pressure. The same group of examinations included tests with physical
loads, with glucose loads, and a rheocardiographic examination of the
myocardium.
The realization of the third purpose involved a determination of
the propagation rate of the pulse wave, piezography, and rheovasography
from the lower extremities, through the employment of a number of
clinico-physiological investigations. The investigations also called
for an X-ray of the thoracic and absominal aortas, the carotid and iliac
arteries, and roentgenokymography of the heart and aorta.
The investigated persons were divided into four groups for con-
venience of examination. The first group consisted of patients in the
first stage of hypertension; the second included patients with diagnosed
atherosclerosis of various localization, and characterized as a rule by
lack of pain or complications; the third was made up of patients whose
305
hypertension was accompanied by other diseases originating from the
atherosclerotic process; the patients of the fourth group did not reveal
any of the diseases listed for the first three groups, but a diagnosis
established a disrupted fatty metabolism, myocardiodystrophy, mild dis-
ruptions of the cardiac rhythm of a functional and organic origin, and
a neurocirculatory dystonia.
An analysis of all results justifies the following basic conclusions
of practical importance .
Conclusions
1. We must considerably improve the diagnosis of atherosclerotic
manifestations in the examination of the flight personnel for purposes
of medical aviation expertise by introducing compulsory functional-
diagnostic investigations that would broaden the possibilities for an
objectively substantiated diagnosis of atherosclerosis.
2. In case of a well- substantiated diagnosis of atherosclerotic
cardiosclerosis, even if not accompanied by an insufficiency of general
and coronary blood circulation, continued flying on supersonic planes
should not be permitted.
3. In the case of atherosclerosis of any other localization accom-
panied by an overall satisfactory functional condition of the cardio-
vascular and other systems, the pilot should be permitted to serve only
in auxiliary types of aviation, if no retraining is required.
h. Of all the information obtained in the functional investigations,
the careful study of the case history, the data on the physical and gen-
eral clinical examinations make it possible to diagnose latent athero-
sclerosis considerably more frequently than would be possible without
the use of the mentioned methods of investigation.
VESTIBULAR REACTIONS UNDER THE EFFECT OF VARIOUS ANGULAR
ACCELERATIONS
S . S . Markaryan
When flying a plane, particularly in advanced flying and catapulting,
the pilot is subjected to the effects of angular acceleration (V. I.
Voyachek, K. L. Khilov, Ye. M. Yuganov and I. Ya. Borshchevskiy) . The
306
intensity and duration of the angular acceleration effect have undergone
substantial changes since the time of the piston- type plane.
There is little reference in the literature to the effect of in-
tensive angular accelerations on vestibular reactions, and a study of
this problem is therefore a matter of practical and theoretical interest.
We have studied the effect of angular accelerations on 13 normal
test subjects at different positions of the body, ranging from a sitting
position, 0° to a 90° angle. The duration, acceleration, and decelera-
tion of the rotation to 1 rps in each case amounted to 12, 9 • 6 and 3
seconds which corresponded to the angular accelerations of 30, h-0, 60,
and 120°/sec . Each test subject participated in h tests. A total of
120 investigations were made.
The test included a recording of the nystagmus with open eyes
looking straight ahead, the pulse frequency, respiration, and an EEG.
The investigations took into account the feeling of the test subjects
and their own account of the duration and nature of the illusion, as
well as the results of their subtraction of figures . Pulse frequency,
arterial pressure, muscular strength of the arm and body stability were
determined before and after the test.
The investigations revealed that the nystagmus fluctuates indi-
vidually at various angular accelerations and body tilts: 5(9)-3l(82)
during the acceleration of rotational velocity and 5(8) -24(6^) during
deceleration. The test subjects examined during their nystagmic re-
action were unable to read the instruments or distinguish the cross
sections of the rings on the choline table for 30 seconds and longer
(the objects appeared to flicker before their eyes).
As the angular accelerations increased, the nystagmic reactions of
the test subjects appeared earlier, and the amplitude in most cases
revealed an increase. But the duration of the nystagmus and the illu-
sions of counterrotation did not always reflect the magnitude of angular
accelerations .
No definite relationship has been found between the extent of the
nystagmus and the sensitivity of the vestibular analyzer. Three to five
seconds after their nystagmus with open eyes, the investigated subjects,
regardless of their vestibular sensitivity, revealed either a "post-post"
The figures before the parenthesis denote the duration of the nystagmus
in seconds, and those within the parentheses the number of nystagmic im-
pacts during that period.
307
or an inverse nystagmus when their eyes were closed. Their duration and
amplitude were occasionally greater than those of the original nystagmus.
The nystagmic reaction under the effect of angular accelerations tended
to decrease as the body was inclined back from the vertical axis. This
became noticeable at a 65 angle of body inclination, and more so at 80
and 90°.
The test subjects experienced illusory sensations under the effect
of angular acceleration. The duration of the counterrotation illusion
in these conditions fluctuated from h to 8J+ seconds. In most cases
the counterrotation illusion diminished with increasing angular accel-
erations. The difference in the duration of the counterrotation illu-
sion, as determined by the angle of body inclination and the angular
accelerations, could not be ascertained. There was no appreciable
difference in the duration of the counterrotation illusion in persons
with a higher vestibular sensitivity and those with a low sensitivity.
Following the cessation of the illusory sensations, the majority
of the investigated subjects appeared to experience such sensations
all over again when they closed their eyes or held their breath, and
sometimes also when they engaged in subtracting figures.
An average pulse frequency increase by 6 beats per minute, and
respiration by 2 per minute, were observable under the effect of angu-
lar accelerations, particularly the acceleration of rotational velocity.
Wo substantial changes in the bioelectric activity of the cerebral cor-
tex were noted under the effect of a constant rotational speed except
in persons with a higher vestibular sensitivity. This group of test
subjects revealed a lower amplitude of the a-rhythm or an intensified
P activity.
In the course of rotation, beginning with a k^° angle of body
inclination the test subjects were under the impression that they were
rotating in an upside-down position and returning to their initial posi-
tion when the rotation stopped. At a 3O angle of body inclination,
they had the sensation that they were rotating while lying flat on their
backs, and when the rotation stopped they felt their bodies rising.
Beginning with a 65 angle of body inclination, and particularly 80-90°,
they felt as if their internal organs shifted upwards, experienced a
constriction of the larnyx and a difficulty in swallowing. Hyperemia
of the eyelid mucosa and an intensified flow of blood into the sclera
vessels were observed in the subjects after these tests.
After a twofold acceleration effect, the test subjects with a
higher vestibular sensitivity revealed a deteriorated feeling, general
weakness, heat in the body and the head, giddiness, nausea, perspira-
tion, cold wrists, and paleness. All these symptoms disappeared 20-lj-O
minutes after the test. A deteriorated feeling in this group of
308
subjects was observed also in the course of rotation as they changed the
position of the head forward, backward, to the right or to the left.
The pulse frequency of these subjects was reduced by 3-I8 beats
per minute after the test. The maximum arterial pressure in most of the
subjects went down an average of 8 mm of the mercury column, and the
minimum pressure in almost all cases rose an average of 11 mm of the
mercury column. These changes were particularly pronounced in the tests
performed under a load. In many of the subjects the muscular efforts
of their hands were 20U kilograms weaker, and their body equilibrium
was upset (as shown by a sensitized Romberg test).
Conclusions
1. The duration and intensity of the nystagmic reaction produced
by the effect of angular accelerations on man depend on the position of
the body in relation to the vertical rotation axis : the nystagmus
gradually diminishes with the increasing angle of body inclination
(from to 90°), while the sensory reaction in the form of a counter
rotation illusion continues.
2. In the first 30 minues or more of the nystagmic reaction it is
impossible to read the aerial navigation instruments or the signs on
the choline table .
3. An upset body equilibrium in various degrees was found in the
majority of the test subjects after the effect of angular accelerations.
k. Changing the position of the head during the rotation or after
one-two effects of angular acceleration produces vestibulo-vegetative
reactions in persons with a higher vestibular sensitivity: general weak-
ness, paleness, perspiration, and nausea.
5. The use of repeated effects of angular accelerations may be
recommended for the purpose of training flight personnel in use of the
vestibular analyzer.
309
REACTIVE CHANGES IN THE INGUINAL LYMPH NODES UNDER THE
EFFECT OF VARIOUS OVERLOADS ON THE ORGANISM OF DOGS
Yu. V. Mashkovtsev
The successful space flights bring up the question of a thorough
and all-round morphological investigation into the effect on the organ-
ism of various factors of these flights. Of particular importance
among them is the effect on the organism of the G-force during the take-
off and landing of the ship. It is important to ascertain not only the
extent of damage produced by such a factor but also, if possible, to
utilize the protective and compensatory mechanisms of the organism to
counteract such effects . The important protective organs are the lymph
nodes in which the antibacterial and antiendotoxic immunity is produced
and the blood cells (lymphocytes) are manufactured. We have not been
able to find any study of the capacity of the lymph nodes to counteract
the effect of the G-force. But we know the work of M. A. Arsen'yeva,
V. V. Antipova, V. G. Petrukhin, T. L. L'vova, N. N. Orlova and S. S.
Il'ina (1961, 1962), who studied the changes in the red marrow, spleen,
and thymus gland of mice under the effect of various factors of space
flight .
The examination of animals after the effects of radiation, follow-
ing an experiment on a vibrating stand and in a centrifuge, as well as
an examination of animals completing a flight in artificial satellites,
revealed that the greatest changes in the hemopoietic organs occur under
the effect of mechanical factors. They showed that an inhibition of
the hemopoiesis took place in the hemopoietic organs (marrow, spleen)
in the first 10 days after the flight in spacecrafts-- this was followed
by a later stimulation of the hemopoiesis, and its restoration by the
30th day.
The purpose of our investigation was to study the condition of one
of the lymphoid organs ( inguinal lymph nodes ) under the effect of G-
forces. The experiment was carried out with dogs which were subjected to
transverse (chest-back) accelerations of varying magnitude and duration.
There were two series of tests. In the first series, the experiment
lasted 3 minutes under an 8-G load factor. In the second series, the
experiment lasted 1 minute under a 12-G load factor. The tests involved
28 mongrel dogs (ik in each series), all of which had been immunized
against the plague 2 weeks before the tests. The animals were sacrificed
by the use of ether fumes in different periods: 1 hour, 2k hours, 3, "J,
15, 30 and 60 days after the G-force effect. The lymph nodes were taken
from the left and right inguinal regions, fixed in "cenkerf ormol " (for-
maldehyde) by the Maksimov method and placed in a Carnoy liquid. The
whole thing was then covered with paraffin. Slices measuring 5u in thick-
ness were stained azure with 11-eosin, and methyl green pyronine by the
310
Brache method. The area of reactive centers was measured and the mytoses
added up on the cross sections of the left lymph stained by the Brache
method .
The changes in the lymph nodes under an 8-G acceleration effect
lasting 3 minutes and 12-G lasting 1 minute are in principle monotypical,
but the duration of the load effect is a determining factor; the changes
in the histological structure of the lymph nodes in the first series are
therefore usually more pronounced and last longer than in the second
series.
The number of lymphocytes in the lymphoid follicles is reduced in
the first hours following the G-force effect in the inguinal lymph nodes
of the dog. In one of the dogs of the first series (l hour) the lymphoid
follicles were found to be destroyed, with the result that the entire
central part of the follicles consisted only of reticular tissue.
In our investigations, the method of measuring the sizes of the
reactive centers was used. Maksimov and Blum (1957) singled out four
stages in the condition of the reactive centers, depending on the hemo-
poietic activity: in the first stage, the centers are the largest and
are characterized by the appearance of individual division cells; in the
second stage, the sizes of the reactive centers are further increased as
is the number of mytoses in them; a decreasing number of mytoses and
small sizes of reactive centers are observed in the third and fourth
stages. The changing activity of the albuminous synthesis in the re-
active centers is just as undulant. This means that the hemopoietic ac-
tivity of the lymph nodes can be judged by the increasing size of the
reactive centers and the increasing number of mytoses in them.
In the first week following the experiment, the reactive centers in
the first series of tests were reduced in size, as compared to the norm,
and the number of division cells in them was small. Beginning with the
second week, the average reactive centers were doubled in size (from
O.kk ram to O.76-O.95 mm ), the area of the largest reactive centers
was also doubled (in seven days), and increased 3-I+ times (in 15 days),
and new reactive centers with indistinct boundaries (first stage cen-
ters, according to Maksimov and Blum (1957)) came into being, as com-
pared with the control centers . The total area of reactive centers
per test sample in the dogs over a period of 7-15 days was 2-5 times
as large as the total area of the reactive centers in the control dogs
(0.5 nim for test animal, 0.2 mm 2 for control animal). The increasing
size of the reactive centers was accompanied by 100-150 percent increase
in the number of the division cells in them with medium lymphocytes pre-
dominating these cells. Hyper chromatic cells appeared at the same time.
The protoplasm of the latter, when stained by the Brache method, had an
311
intense rose color, and I-3 large pyronophilic nucleoli were noted in
the nucleus. In 3O-6O days the cortical substance of the lymph nodes
retained the usual appearance in only 2 dogs of this series. Two other
animals revealed a sharp irritation of the lympho-poietic growth. In
one animal, killed 30 days after the test, the average size of the re-
active centers increased 5 times, the area of the most reactive center
15 times, and the number of the reactive centers was doubled, in com-
parison with the lymph nodes of the control dogs. The number of division
cells in the reactive centers of that dog was 2.6 times larger than that
of the control dog. In the animal killed 60 days later, the average
size of the reactive centers was doubled, the area of the largest reac-
tive center showed a fourfold increase and the number of division cells
in the reactive center increased 2.6 times in comparison with the control
animal .
In the second test series, the increasing sizes of the reactive
centers (1.5 times) were noted on the third day after the experiment
(from 0.0U mm^ to 0.06 mm^) . The area of the largest reactive centers
was increased 3-^ times, and the number of the reactive centers them-
selves was doubled as compared to the control data. New reactive centers
were seen to appear. There was a simultaneous 50-100 percent increase
in the number of division cells in the reactive centers . In the second
week after the experiment, the substantia corticalis of the lymph nodes
returned to normal in all the dogs except two (15-3O days after the ex-
periment) in which the reactive centers increased 100-70 percent and
the number of division cells in them 200-7° percent, as compared to the
control data. Two months after the experiment, the substantia corticalis
had regained its usual appearance and showed a few small reactive centers.
An increase in the number of macrophages was noted within 1 hour
after the experiment in the intermediate sinuses of the substantia
medullaris of almost all the lymph nodes under observation. The reticu-
lar cells lose their processes in this connection, grow larger in size
and become rounded, and their protoplasm becomes oxyphilic. Captured
erythrocytes can be seen in the protoplasm of some of the macrophages.
One day after Ine experiment, the pulpy columns of the substantia
medullaris in both dogs of the first series and one dog of the second
series revealed the presence of neutrophilic leucocytes which disap-
peared by the third day.
The intensification of the hemopoietic function in the lymph nodes
during the 7-15 days after the experiment (first series) is, in our
opinion, a compensatory mechanism which maintains the number of lymphocytes
in the blood at a permanent level. The intensified formation of macro-
phages we observed in the first hours after the G-force effect is ap-
parently a characteristic result of the load factor and coincides with
the investigations of the blood of the animals in the Soviet artificial
312
satellite which revealed an intensified phagocytic activity of the leu-
cocytes (0. G. Gazenko (1961)).
Thus the load factors in the first series (which lasted longer) pro-
duced a more powerful effect on the lymphopoietic tissue as compared to
the shorter but heavier loads of the second series. The destruction of
the lymphoid follicles in the first days after the G-force effect was
eventually replaced by a regeneration phase. The proliferative proc-
esses in the lymphoid follicles were depressed in the week after the
overload, and the regenerator processes originated at the end of the
first week. An intensified but short-lived formation of macrophages
occurred in the sinuses of the lymph nodes in the first hours after
the G-force. The histological structure of the lymph nodes returned
to normal 2 months after the G-force effect.
THE DYNAMICS OF THE MORPHOLOGICAL CHANGES IN THE CEREBRAL
CORTEX OF DOGS FOLLOWING THE EFFECT OF A TRANSVERSE
ACCELERATION
D . I . Medvedev
The changes occurring in the CNS and, particularly, in the cerebral
cortex under the effect of accelerations have been studied primarily by
way of physiological investigations and clinical observations. These
efforts have focused attention on the disturbances of the visual func-
tion (Frankenhaucer (1957), Miller, Mitchel, Riley, Bondurant and
associates (1958), A. B. Flekkel ' , E. V. Marukhanyan (1959), etc.,) the
changes in the conditioned reflex activity (V. I. Babushkin, P. K. Isakov,
V. B. Malkin, V. V. Usachev (1961)), and the bioelectric activity of the
cortex (Jasper and associates (19^2), A. Ya. Rosin, G. P. Mikhaylovskiy,
P. M. Suvorov (1959), A. N. Razumeyev, p. M. Suvorov (1962)). Thus the
two-phase feature of the changes in the bioelectric activity of the
cortex under the effect of accelerations has been established by Jasper
and his associates. The first phase of these changes indicates the ap-
pearance of a stimulus in the CNS; the second stage reflects the develop-
ment of inhibition processes in the cortex.
V. I. Babushkin and his associates explain the disruption of the
conditioned reflex activity occurring after the acceleration effect "by
the development of an external inhibition in the cortical cells of the
motor analyzer " .
Most of the authors associate the functional disruptions observable
in the cortex with the disturbed activity of the cardiovascular system
313
and special hemodynamic conditions arising in the organism under the
effect of acceleration (V. I. Babushkin (1959)> A. Ya. Rosin and asso-
ciates (1959), E. V. Marukhanyan (1961), Yu. Ye. Moskalenko, 0. G.
Gazenko and associates (1962), etc.).
Very few morphological investigations have been made of the effect
of acceleration on the cortex. A. S. Barer (1958) observed the appear-
ance of cells with a vacuolar degeneration in the brain, a considerable
number of amitoses, and a thickening of the blood vessel walls after
numerous acceleration effects. I. M. Khazen (1958) also discovered a
distinct amitotic division of nerve cells in the brain. The appearance
of corrugated cells and shadow cells in the cerebral cortex of mice,
following their flight in artificial satellites, as well as the solu-
tion of the Nissl substance and the resorption of individual cells or
groups of cells with lucid foci are indicated in V. G. Petrukhin's work
(1962).
This report deals with a study of the dynamics of the morphological
changes in the motor analyzer region of the cerebral cortex of dogs under
the effect of a single transverse acceleration. Two series of tests were
made: in the first, the animals were subjected to an 8-G acceleration
effect for 3 minutes; in the second, to 12-G for 1 minute.
One hour and 1, 3, 7, 15, 30, and 60 days later the dogs were
killed with ether fumes, and samples were taken for microscopic investi-
gations. Small pieces of brain were placed in 10 percent formalin, and
96 alcohol as well as Carnoy liquid, and then covered with celloidin and
paraffin. The test samples were stained with hematoxylin-eosin and
thionine by the Nissl method, and pyronine by the Brache method, in order
to find ribonucleic acid, and by Schiff 's reagent with periiodate for the
purpose of detecting mucopolysaccharides and glycogen. The visible
changes revealed in an external examination and the opening of the brain
consisted merely of blood-filled brain vessels and soft meninx.
An investigation of the histological preparations in tne afore-
mentioned region of the cortex revealed small hemorrhages, detectable
only under a microscope, into the brain tissue. In many cases, the
vascular walls of the small arteries were considerably disintegrated;
occasionally they were ruptured. Hemorrhages were found mostly in the
gray substance region or on the boundary between the gray and white
substances of the cortex, especially in the dogs of the first series of
tests which had been killed 1 hour, 1 day and 3 days after centrifuga-
tion. Only a few hemorrhages were observed shortly after the experiment
in the second series of tests.
An examination of the nerve cells, stained by the Nissl method,
showed that the nerve cells of various cortical layers react in differ-
ent ways to the acceleration effect. It is a known fact that Nissl
classified the nerve cells as karyochromic and somatochromic, depending
JU
on the relationship between the nucleus and the protoplasma. He defined
the karyo chromes as cells in which the nuclear mass predominated the
protoplasmic mass (in the cortex these are known primarily as cells of the
II, IV and VI layers). The somatochromes are cells with a large quan-
tity of protoplasm (most of the pyramidal cells of the III and V layers
of the cortex) .
Characteristic of the karyochromic nerve cells of the II and VI
cortical layers of the motor analyzer are chromatolysis and cytoplasm
vacuolization. The Nissl substance of many such cells disappeared
almost completely, and the cells took on the form of a hollow vesica
containing a well-stained nucleus. All that could be seen between the
nucleus and the cell membrane were almost colorless cytoplasmatic col-
umns and small individual islands of Nissl substance.
The Nissl substance was seen to concentrate, after centrifugation,
around the nuclei of the nerve cells in the gigantic pyramidal Betz's
cells; the sorptive properties of the cytoplasm and karyoplasm were
enhanced, and the cells began to be diffusely stained with thionine.
At the end of this process, the boundary between the nucleus and the
cytoplasm became almost indiscernible. At the same time, the periphery
of the cytoplasm was found to be free of stain, representing an optically
empty space. Many pyramidal cells in the third layer of the cortex were
also found to be rapidly stained with thionine .
The above-described changes of the nerve cells were more pronounced
in the first series of tests than in the second. In the course of time,
all these changes were reversed, and a month later, particularly 2
months after the effect, most of the nerve cells of all the cortical
layers acquired the usual microscopic structure.
Paralleling the development of these structural nerve -cell changes
in the first 2 weeks after the effect was the growing activity of oligo-
dendroglia whose cells were grouping around the nerve cells in larger
than usual quantities. The introduction of oligodendrocytes into the
cytoplasm of the nerve cells and the death of individual nerve cells
were noted occasionally. These phenomena could be most clearly observed
about a week after the effect.
An increase in the number of binuclear cells was noted in later
periods. The frequent shifts of the nucleoli toward the periphery of the
nuclei, and frequently even the complete escape of the nucleoli from the
nerve cell nuclei, attracted special attention. In this case the nu-
cleolus was found either in the cytoplasm of the nerve cell or even
emerged outside the cell, remaining alongside it.
In both test series, the amount of ribonucleic acid in the nerve
cells of the cortical region investigated 1 hour after the effect was
found to have been considerably increased. It was somewhat reduced by
315
the end of the first day, "but was still above the norm. Fifteen, 30,
and 60 days later the amount of ribonucleic acid in the nerve cells of
the test animals was exactly the same as in the control dogs .
An intense Schick-positive staining of some of the cytoplasm of a
number of Betz's ganglionic nerve cells was detected in some of the
animals of the first test series in the early stages (l hour and 3 days
after the effect). Such staining, but considerably less pronounced,
was occasionally observed in the dogs of the second test series in
later periods ( 30 days after the effect). The nature of this staining
process--and its connection with the effect characteristics — is still
unclear .
The investigation has thus shown that, under the effect of the above-
mentioned accelerations, a large number of morphohistochemical changes
take place in the area of the motor analyzer of the dog's cerebral cor-
tex. Some of those changes (the hemorrhages, for example) are un-
doubtedly induced by the acceleration, while others possibly reflect
the compensatory reactions of the nerve tissue. We are inclined to
the latter opinion, in view of the fact that the above -de scribed changes
of the Nissl substance, the enhancement of the sorptive characteristics
of the protoplasm, and the increase in the number of hyperchromic cells
among the large and small pyramids of the III and V cortical layers, as
well as the vacuolization of the karyochromic cells of the II and VI
layers of the cortex, are in many ways similar to the morphological
pictures in the cerebral cortex described by B. N. Klosovskiy and Ye. N.
Kosmarskaya (1961) during the period of carotid inhibition. This as-
sumption is confirmed by the above- cited observations of the physiolo-
gists (Jasper and associates (I9I+2), and V. I. Babushkin and associates
(1961)). From these positions, the increasing content of ribonucleic
acid in the nerve cells, observable in the first periods after the ef-
fect, may be regarded as a compensatory increase in the ribonucleic
proteins, that is, as a reaction to the functional tension experienced
by the cortical cells under the acceleration effect.
At the same time, the few instances of nerve-cell death and the
increasing number of binuclear cells are evidence of definite reactive
changes in the cerebral cortex. It should be admitted, however, that
these phenomena are very few in number, and that the overwhelming
majority of the changes occurring after the acceleration effect are of
a reversible nature.
A comparison of the results of the first and second series of tests
shows that the changes in both series are of a homogeneous nature. But
the changes occurring in the first series of tests are more pronounced
than in the second.
316
THE EFFECT OF A PROLONGED HYPOKINESIA ON THE HUMAN
BLOOD CIRCULATION
A. L. Myasnikov, R. M. Akhrem-Akhremovich, L. I. Kakurin,
Yu. T. Pushkar', N. M. Mukharlyamov, V. S. Georgiyevskiy,
Yu. N. Tokarev, Yu. A. Senkevich, B. S. Katkovskiy,
A. N. Kalinina, M. A. Cherepakhin, V. A. Chichkin,
V. K. Filosofov and P. G. Shamrov
Hypokinesia in man has now attracted the attention of specialists
in various fields of medicine. Industrial physiologists see in this
the necessity of solving not only special problems "but also social ones,
inasmuch as any technological advance and improvement of living stand-
ards are in the long run conducive to a reduced use of the muscles.
In clinical medicine, it is important to establish the effect of pro-
longed restriction of mobility associated with confinement to bed dur-
ing a pathological process. This problem is of particular importance
for the specialists in aviation and space medicine. Although there are
grounds for the belief that technological advances will lead to the
development of systems in which the effect of acceleration, vibration,
and isolation on the flight crew will play a secondary part, neverthe-
less, the duration of space flights by man will be considerably ex-
tended. Prolonged weightlessness will result in the human adaptation
to new conditions, and a reduced tolerance of physical loads in condi-
tions of higher gravitation.
The reduction of the muscular effort and the lack of a hydrostatic
blood pressure will play a definite part in the disruption of the mech-
anisms regulating the blood circulation in man in a state of prolonged
weightlessness .
This investigation involves the use of a regimen of confinement to
bed as a factor approaching certain hypodynamic and circulatory effects of
weightlessness. The test subjects were four men, 22 to 2k years of age,
judged to be in perfect health by a commission of medical experts.
These men were kept in a horizontal position for 20 days, and allowed to
sit up in a spacecraft once every 3-U days. They had been subjected to
all sorts of clinical and physiological examinations before and after
the experiment, including an examination of the pulse, arterial pressure,
the blood-flow rate, venous pressure, the mass of the circulating blood,
the beat and minute volume, the rheography of the head and shins. An
analysis of the dynamics of the cardiac activity was made by the
Blumberger and Holdak polycardiographic method, which made it possible
to determine the time of the asynchronous, isometric, and isotonic
contraction of the heart, the tension phase, the protodiastolic period,
the duration of the mechanical and electrical systole and diastole of
the left ventricle, and the intrasystolic indicator. The minute volume
of the heart was determined by the method of diluting T-1824 paint
317
(Stuart-Hamilton) and by a physical method (Bremser-Ranke); a calculation
was made also of the peripheral resistance.
The investigations were made in a state of rest and after a func-
tional load. These included 30 rhythmic knee-bends, each lasting 1.5
second, and passive orthostatic shifts of the test subjects on an inclined
table, and also 20-minute stationary periods.
Compared to the initial data, the changes of the mentioned indicators
during the confinement to bed were as follows : the pulse frequency
dropped an average of Ik beats per minute (from 9 to 25 ), and the pulsing
arterial pressure was found to be reduced in all the test subjects by an
average of 11.2 mm Hg (from h to 19 ). The beat volume was reduced by an
average of 6 milliliters, and the minute volume by 1.6 liters (from 1
to 2.2). The peripheral resistance rose an average of 511|.2 dyne/cm^/
sec. Two of the test subjects revealed a shorter period of isometric
contraction (lto 0.015 second, and another to 0.02 second) and a 5 per-
cent increase in the intrasystolic indicator. A slower blood-flow rate
and a lower venous pressure (by 50 and 20 mm on the aqueous column)
were observed in two of the test subjects. The rheographic data on the
flow picture revealed a slower rate of blood flow into the shin vessels
and no substantial changes in the blood flow into the cephalic vessels.
After the period of confinement in bed the following changes oc-
curred, as compared to the initial data : the pulse frequency in all the
test subjects rose from l8 to 3U beats per minute, the increase in the
pulse pressure was accompanied by a corresponding rise in the minute vol-
ume, and the peripheral resistance was reduced on an average of 238
dyne/cm^/sec.
The knee-bend exercise test revealed a rising pulse frequency, which
is characteristic of muscular effort, and changes in the arterial pres-
sure and the phases of the cardiac cycle : a shorter phase of the iso-
metric and isotonic contraction of the mechanical systole, and an increas-
ing intrasystolic indicator. Before beginning of the bed- confinement
regimen, these changes were insignificant; restoration as a rule occurred
three minutes after the knee-bending exercise, while after the end of
the bed- confinement period, particularly in the first days, these
changes were greater and restoration could not be observed in the first
7 minutes after the end of the test. Although the mentioned changes
did not extend beyond the range of physiological fluctuations, their
tendency was indicative of a weakening of the organism's regulatory
systems .
In the case of a passive upright posture, the diastolic pressure
rose after the experiment by 5-15 n™ Hg in the second and fourth posi-
tions (with the head up) as compared with the initial data. A rheographic
318
examination revealed a reduced flow of blood into the shin vessels (a
lower amplitude) in k- of the test subjects, and into the cephalic ves-
sels in 2 of the subjects. These changes were more pronounced after
the bed- confinement regimen. At the end of the upright posture test
following the bed- confinement regimen, 2 of the test subjects showed
pronounced changes in the form of the shin reogram; the latter was
characterized by the appearance of a systolic plateau and an increase
in the diastolic wave, indicating a changing tonus of the vessels in
the lower extremities .
The data produced by an active orthostatic 20-minute test of 3 sub-
jects, as compared to the data obtained under the same conditions before
the test, revealed a faster pulse frequency, an increasing diastolic
pressure, and reduced pulse pressure. Subjectively, that condition was
characterized by general weakness, giddiness, perspiring scalp, and in
some cases nausea. An objective investigation revealed a considerable
paleness, visible mucosae, and an acrocyanosis. The clinical picture
resembled that of a presyncope.
In the case of a person kept in a horizontal position for 20 days,
his muscular activity previously used to compensate for the force of
gravity to maintain the body in a vertical position, was not utilized
to an insignificant extent. There was a decrease also in the hydro-
static blood pressure which, as a stimulus of the sympathetic regulators
of the blood circulation, frustrated the adaptive capacity of the car-
diovascular system to the changing direction of the force of gravity.
It may be assumed that a similar tendency of the functional changes
of the cardiovascular system will occur in a person returning to ter-
restrial gravitation after a long period of weightlessness.
SOME PROBLEMS OF PROFESSIONAL SELECTION
V. D. Nebylitsyn and B. M. Teplov
The required preliminary conditions for the efficient and effective
selection of people for a certain type of activity are :
1. A familiarity with the actual structure of the working operations
and practical requirements of the type of activity under consideration.
2. The development of the most suitable selection methods which
must meet the following minimum requirements : theoretical substantiation,
practical authenticity ("validity"), statistical reliability, and the
319
highest possible standardization of the tests. These requirements are
similar to those applying to most of the tests in professional, selec-
tion used in the western countries, but only to a point: the difference
is that according to the apologists for the present practice of "testol-
ogy", the requirements of theoretical substantiation do not and cannot
apply, which makes "testology" a pseudo-scientific system of blind,
roughly oriented, and empirical tests. We, on the other hand, propose
the requirement of theoretical substantiation and a familiarity with the
psychological nature of the applied tests. This requirements must be
decisive in the system of selection, and it should be observed in order
to reduce the possible errors to a minimum.
3. A precise and definitive quantification of the evaluations.
This condition may seem to be technical rather than basic, but we are
inclined to ascribe first-rate importance to it, inasmuch as without a
quantitative approach to the selection parameters, there would inevit-
ably result a distribution of candidates only on the basis of descrip-
tions and undifferentiated subjective characteristics. It is not at all
necessary to insist on absolute quantitative indicators from the very
beginning. In practical problems this requirement may be met (at a
certain level of our knowledge) by determining the rank, that is a rela-
tive evaluation to some extent (which incidentally may coincide with the
absolute evaluation), indicating the individual's status in the given
concrete population or in relation to some definite statistical "norm".
The purpose of every selection is to predict at least two basic
characteristics of the individual: first, his educational progress, that
is his "capacity for learning", and, second, his efficient behavior
under any complex situation including extreme conditions, that is his
"operational effectiveness". These two characteristics should be care-
fully separated, for even though they occasionally coincide, there are
numerous examples in the literature of an opposite nature; for example,
an operator showing excellent progress in training, such as flying a
plane, may prove to be inconsistent in a battle situation, which may
require a number of individual qualities in addition to his formal
knowledge and habits. It is also true, however, that successful activ-
ity in an operational situation is impossible without a good preliminary
training. The determination and prediction of the ease with which a
candidate may acquire the required system of knowledge and habits, and
his "learning capacity", are therefore a matter of great practical
importance .
The tests used in foreign countries, such as "instrument" tests,
cannot pretend to detect any dynamic indices. It should always be kept
in mind, however, that selection as now practiced is primarily a selec-
tion for purposes of training in a certain profession or skill, for
learning a certain system of habits and knowledge. But if that is so,
and if the prime purpose of the selection is the singling out of certain
320
persons likely to acquire the system of required habits and knowledge
and who show a better capacity for learning with relative speed and
success, would it not be practical, instead of trying to detect the habits
already possessed by the individual (which in effect the current tests,
attempt to do), to try and find out the rate and success with which the
individual might acquire new habits and knowledge specific to his
selected profession or skill?
We believe the answer to this question may be only positive: in the
case of activity involving primarily a system of a certain set of habits
and skills, the specific capacity will assert itself in the form of the
individual's ability to acquire such habits and knowledge. Thus, the
above proposal amounts to the replacement of the procedure involving
the establishment of the statistical picture of available habits and
knowledge by a system of checking and measuring a given individual ' s
capacity for acquiring new habits specific to a given activity for
learning, training, and exercising. In this case the quantitative index
might be speed of reaching an individual "ceiling", the level of that
"ceiling", the scattered results obtained in the process of learning,
the number and distribution of mistakes, etc.; the conclusion in such
a case should be based not on any single index but on a large number of
indices whose relative significance should be determined beforehand.
But the actual working situation requires not only a great deal of
training on the part of the operator but also a large number of strictly
personal qualities, some of which can be easily cultivated and developed
while others are more persistent, inert, and practically unaffected by
the life of the individual. The characteristics of the first category
include primarily the individual's moral qualities and his volitional
characteristics. The qualities of the second group, as manifested in
the man's behavior, are closely associated with the individual's neuro-
physiological characteristics, and that association, even if not fully
detected, can be more or less pointed out or presumed. We have in mind
such individual characteristics as emotional balance, self control, a
sense of timing, a capacity for concentration, a psychic endurance, the
degree and distribution of attention, reorientation, etc. All of these
may be interpreted as more or less related manifestations of the indi-
vidual's nervous system, and as such might lend themselves to a fairly
exact interpretation and experiment definition.
Despite the considerable difference between these two groups of
personal qualifications, both play a very important and probably de-
cisive role in the description of the individual which is directly as-
sociated with his "operational effectiveness" and which we shall refer
to as "reliability", bearing in mind first of all the "durability",
stability, and the persistence of the individual in the performance of
his functions. Here the role of the second group of characteristics,
associated with those of the individual's nervous system, apparently
321
increases with the growing complexity of the actual situation and the
increasing responsibility of the person involved in it. If in many of
these situations (possible the majority of them) the particular nervous
processes of a machine-operating individual are not very important, the
characteristics of the nervous system in situations characterized by a
high degree of tension ("extreme situations") do make a difference: some
individuals will act in such situations better than others just because
there is a greater affinity between their nervous system and the condi-
tions of work. The unique "compensation" for the missing character-
istics, which are occasionally extraneous to the characteristics of the
nervous system, becomes increasingly difficult in such extreme situations.
In such cases, the individual's deeply ingrained natural characteristics
take over, and these include the inborn characteristics of his nervous
system.
If a definition of these characteristics is important in order to
help the individual determine the ways and means of "compensating" for
the qualities he lacks, where such compensation is possible and prac-
ticable, it is all the more necessary in the selection of candidates for
work in extreme conditions. Herein lies the chief reason for studying
the characteristics of a person's nervous system.
THE SANITARY ASPECT OF THE WORKING CONDITIONS
AROUND ULTRAHIGH FREQUENCY GENERATORS
M. I. Netreba
The service personnel of radar stations and the people within the
range of their radiation are subjected to the effect of the UHF field.
The extent and nature of the harmful effect are determined by the work-
ing conditions in servicing the generators and by their parameters which
include : the power of radiation, the wavelength, the pulse frequency and
its duration, the distance from the radiation source, etc.
The main parameter determining the evaluation of the working condi-
tions among UHF installations from a hygienic point of view is the
amount of energy affecting the service of the body. The radiation time
and the density of the UHF-field current must be controlled in order to
evaluate the effect.
Different types of UHF electromagnetic oscillators have been intro-
duced into the national economy as well as in the Civil Air Fleet in recent
years. UHF generators of the centimeter band (35-3 cm) are used on a large
scale in the Civil Air Fleet.
322
The introduction of these installations was followed by complaints
to the Ukrainian Territorial Administration of the Civil Air Fleet about
the deteriorating health (of the workers servicing the UHF generators.
The workers complained of headaches, fatigue, sleeplessness, general
weakness, pain in the pupils of the eyes, the heart, etc. Most of the
complaints came from those employed directly in the radar installations.
These deteriorating effects were usually noted by the end of the
working day. These reports prompted the medical service of the Ukrainian
Territorial Administration of the Civil Air Fleet to make a study of the
working conditions at the airfield radar stations. Measurements made
with the "Medik" Mi|— 2 apparatus (sensitivity 0.5 microwatt/cm^) at vari-
ous distances from the radiation sources (up to 600- 950 meters) showed
the highest radiation density (over 100 microwatt/cm2) on 13 installa-
tions at distances of 25 to 600 meters from the radiation source (an-
tennas). Intensities in excess of 10 microwatt/cm2) were established
on the work benches as well as in the area of 15 installations . It
should be pointed out that (a) the measurements were made after the
antennas had been brought to a stop, as we do not know how to make such
measurements with a rotating antenna, and (b) the highest densities of
the UHF current were found mostly at the large circular scanning radar
stations. The radiation of the dispatcher installations was, as a rule,
within the permissible range.
The duration of the working day plays a considerable part in the
UHF-field effect on the service personnel. Wot at all the installations
was the working day of the personnel subject to the existing regulations .
Thus, at four of the investigated installations the working day was arbi-
trarily extended (for a number of reasons) to 8-10 hours, instead of the
6-7 hour day. Measurements revealed higher densities of the UHF-field
current at those installations (over 10 microwatt/cm2) .
The first complaints about health came from the above-mentioned four
installations . Later, when complaints began to come in from persons
working a normal workday on UHF oscillators, a thorough medical checkup for
service personnel and a study of the working conditions at those instal-
lations were instituted.
The maximum UHF radiation density around the dispatchers working on
the landing radar stations amounts to form to 10 microwatt/cm2j around
radio technicians and engineers serving the huge stations intensity
varies from 1.5 to several hundred microwatts per square centimeter.
The radio technicians are subjected to a higher radiation intensity dur-
ing the tuning and adjusting of their antenna devices, and frequently
they also receive the radiation from the neighboring radar stations as
a number of airports have two radar stations in the same area. Thus, it
323
has been established that at some radar stations the density of the UHF
radiation amounted to 60-600 microwatt/cm at distances of 25 to 600
meters from the antenna. In most cases it takes 1.5-2 hours to tune and
adjust the antennas.
An analysis of the medical examinations of the service personnel
revealed that the subjective complaints had come first from the shift
engineers and radio technicians, then from the dispatchers and par-
ticularly radio technicians working overtime and finally from the radio
technician working a normal workday.
A clinical investigation of 10 radio technicians and shift engi-
neers on a longer workday revealed very pronounced functional changes
(in the form of asthenic and vegetative reactions) in their various
organs and systems. The latter were manifested as a weakening of the
stimulating processes, sluggishness, increased fatigability, pains in
the cardiac area and diffuse dermography. Similar disruptions were
found in three of the workers ( senior and on-duty engineers and radio
technicians). One of them, with advanced symptoms, was removed from
his radar station job altogether, and the other two for 6 months. Changes
in the peripheral blood were found in 11+- engineers and radio technicians :
an increase in the percentage of reticulocytes (from 1 to 3 percent); no
such changes were noted in the persons not connected with radar station
work. All these symptoms were discovered in the men working at the radar
stations for 5 years and longer. Pronounced changes in the organon visus
were found in one case (the man had been working at a radar station over
10 years).
Organic changes were not found in the cardiovascular and nervous
systems of those investigated. It should be pointed out that the short-
ening of the workday for service personnel at the above-mentioned k sta-
tions and at other installations, together with additional changes, in-
cluding the introduction of special shielding devices for the workers,
have reduced the effects on the peripheral blood and the nervous system
to a vanishing point.
It was at this time that the medical service looked into the mat-
ter of soft X-ray radiation in the control panel rooms of the radar
stations. Such radiation was found only in the control panel room of
the Radian station where it was 10 times above the norm. It was not
found at any other radar station. Laboratory tests were made at the
same time of the microclimate in the working buildings, including the
measurement of the temperature and air humidity, the COo content at the
beginning and the end of a work shift as well as the noise level in the
buildings. Artificial and natural illumination were also measured.
32U
The results of these investigations revealed that the air humidity
in the working buildings was normal. The temperature in the control
panel rooms was above the comfort level, the illumination of the indi-
cator screens was inadequate, and the C0 ? content in the building was
somewhat increased. The noise was found to be within the permissible
range except in the rooms containing the receiving and transmitting ap-
paratus where it exceeded that level by 12-kO decibels. The ozone and
nitrogen oxide content in the machine halls was within the normal range.
It may be seen from the above that the indicators of the micro-
climate in the working buildings do not as a rule exceed the established
norms, nor do they produce any adverse effect on service personnel.
Conclusions
1. The regulations governing the duration of the workday for radar
station engineers and radio technicians should be strictly observed.
2. Individuals should not be hired for these installations without
preliminary special and thorough medical examinations.
3. Individuals whose health has been specifically affected in any
way by UHF radiation should be transferred temporarily to other jobs.
k. Individual protective facilities should be developed for service
personnel engaged in tuning and adjusting the antennas as well as in
the repair of the indicator facilities.
5. All required protective measures (screening, etc.) should be
rigidly observed.
6. No communication or other facilities should be located within
the danger zone of the radar station.
THE ROLE OF THE SINOCAROTID REFLEXOGENIC ZONE IN THE
REACTION OF THE BLOOD SYSTEM TO REDUCED BAROMETRIC PRESSURE
Yu. V. Nikolayenkov
A study of the ways in which the compensatory changes in the blood
system are developed and regulated in conditions of low barometric pres-
sure is a matter of great interest for the development of methods designed
325
to increase the organism's resistance to unfavorable conditions of the
external medium. It is very important to study the control of the com-
pensatory reactions of the blood system under the alternating effect of
reduced barometric pressure, inasmuch as this particular effect is a
frequent occurrence in the external medium peculiar to the work of the
flight personnel. The investigations of the role of the sinocarotid
reflexogenic zone in the reaction of the blood system to low barometric
pressure are few and contradictory. L. I. Ardashnikova (1952), Grant
(l95l)j Terzioglu, Geral', and Bardavit (1955) disprove the participa-
tion of that zone in the mechanism of the mentioned reaction. N. N.
Beller (1957) believes that the chemoreceptors of the sinocarotid zone
do not participate in the redistribution reactions but play an essential
part in the mechanism of the true erythrocytosis occasioned by a re-
duced barometric pressure.
Our investigations of 11+ adult male dogs involved the changes in
the peripheral blood and bone marrow under the effect of alternating
low barometric pressure within 267 mm of the mercury column, produced
by a series of "ascents" in a pressure chamber to an "altitude" of 8,000
meters for 2 hours in the course of 6 days. The speed of the "ascent"
and the "descent" was 15-20 meters/sec. The peripheral blood indicators- -
the hemoglobin content, the number of erythrocytes, reticulocytes, and
the hematocrit indicator- -were examined before the "ascent", immediately
after the "descent", and then at 30-minute intervals over a varying period
of time (from .5 to 1.5 hours) as well as 2k hours after the series of
"ascents". Spinal punctures were made before and after the series of
"ascents". The functional condition of the erythropoiesis was studied by
means of a radioactive iron isotope (Fe59). The acid erythrogram method
was used to investigate the stability of the erythrocytes.
After remaining at an "high altitude" for a while, the intact animals
revealed an increasing content of erythrocytes (from 205,000 to 1,675,000
per 1 mm-J), hemoglobin (from 5 to l8 units on the Sali scale), reticulo-
cytes (from 3 to 20 ^/00 and a higher hematocrit indicator (from 3.5 to
9.5 units). Thirty to sixty minutes after the descent, most of the
peripheral blood indicators returned to the initial position.
After a series of "ascents", the dogs revealed an increasing quan-
tity of erythrocytes (by 650,000-900,000 per 1 mm- 5 ), reticulocytes (by
12-15 /00), a growing hemoglobin content (by 8-11 units on the Sali
scale), and a higher hematocrit indicator (by k-6 units). The bone-
marrow picture indicated an increasing content of the elements of an
erythroblast series and an accelerated maturation of the erythroblasts
(an increase in the quantity of oxyphilic erythroblasts by 11-lU per-
cent, according to partial erythrograms ) .
326
The tests involving the intravenous introduction of labeled iron
(in the form of ascorbate Fe59, l microcurie per 1 kilogram of -weight)
revealed the characteristic features of its utilization by the animals
after a series of "ascents" in a pressure chamber. Eight to 11 percent
of the iron introduced into the control animals was still there 6 hours
later. On the second day, the quantity of the iron in the blood re-
vealed a gradual increase reaching a maximum by the 9-10th day (U3-V7
percent of the introduced dose). Only 3-5 percent of the iron intro-
duced into the animals 1 blood after a series of "ascents" remained in
it 6 hours later; the maximum recurrence of the radioactive iron was
observed on the fourth and fifth day when it amounted to 93~95 percent
of the introduced dose.
An investigation of the erythrocyte distribution by stability, by
the method of acid erythrograms , revealed that on the first or second
day the reduced barometric pressure produces a stretched erythrogram,
and a rise of its right wing which is indicative of an increasing num-
ber of stable erythrocytes in the blood. A drop in the stability of all
the erythrocytes, however, was noted in the following days, and mani-
fested in a shift of the erythrogram to the left. On the fifth arid
sixth days of the effect, and 2k hours after the series of "ascents",
the stability of the erythrocytes began to rise again. The normaliza-
tion of the peripheral blood was noted 7-10 days after the end of the
"ascent" series, and of the bone marrow after 1-1. 5 months.
A twofold denervation of the sinocarotid zones produced anemia.
Following restoration of the blood composition after denervation, the
animals were subjected to the effect of a reduced barometric pressure.
Immediately after the "descent", the blood of the animals with denervated
carotid sinuses revealed the same changes as the intact animals.
But the normalization of the peripheral blood following the "descent"
of such animals was usually delayed. Thus, 3O minutes after the "descent",
these animals unlike the intact animals, not only failed to show a de-
crease in the number of erythrocytes, the percentage of hemoglobin and
the hematocrit indicator, but in a number of cases they even revealed
a tendency to increase. The normalization of the peripheral blood was
3O-6O minutes later than in the intact animals.
No changes were found in the peripheral blood of the operated ani-
mals after a series of "ascents". The punctated bone marrow indicated
some irritation of the erythroblast growth, but no accelerated matura-
tion of the erythroblasts was observed. Only 6-8 percent of the radio-
active iron introduced into the operated animals after a series of
"ascents" was found to have remained 6 hours later; the maximum recur-
rence of that iron was observed 7-8 days later, when it amounted to
63-72 percent of the introduced dose.
327
An investigation of the acid erythrograms showed that the phasic
stability changes observed in the intact animals under the effect of low
barometric pressure were absent in the operated animals. The erythrocyte
stability either did not change at all or showed a tendency to decrease.
The increasing number of erythrocytes, the higher hemoglobin per-
centage and hematocrit indicator, as well as the reticulocytes and the
growing erythrocyte stability noted in the intact animals, are indica-
tive of an intensified erythropoiesis; this is confirmed by the bone-
marrow picture and the investigations involving the use of a radio-
active iron isotope, as it is known that the radioactive iron intro-
duced intravenously disappears from the plasma in the first hours and
reappears in the blood as part of the hemoglobin of the newly formed
erythrocytes .
The changes in the peripheral blood immediately after the "descent"--
erythrocytosis, a higher hemoglobin percentage and hematocrit indicator,
reticulocytosis, and increasing erythrocyte stability in the first two
days--are occasioned by the redistribution of the regular blood elements
and of the ejection of the reserve of young erythrocytes from the bone
marrow.
The denervation of the carotid sinuses disrupts the usual reaction
of the blood system to reduced barometric pressure : the irritation of
the erythroblastic series, as confirmed by investigations with the use
of radioactive iron, reveals a disruption of the erythroblast matura-
tion process, a delayed restoration of the peripheral blood following
the effect, and a disruption of the phasic changes of the erythrocyte
stability.
The results of the tests indicate that the sinocarotid reflexogenic
zone is an important link between the reaction of the blood system to
reduced barometric pressure and the related oxygen starvation of the
organism. The exclusion of the reflex impulse from the interoceptive
zone of the carotid sinuses results in a disruption of the usual reaction
of the blood system to hypoxia. It also disrupts the processes of
blood formation, distribution, and destruction.
328
EVALUATING SOME OF THE ORGANISM'S REFLEX REACTIONS TO
BREATHING UNDER INCREASED INTRAPULMONARY PRESSURE
P. V. Oblapenko
A considerable increase in the intrapulraonary pressure over a more
or less lengthy period of time (several minutes) is something unusual
for the organism, as in its entire evolutionary development the or-
ganism had to deal with such phenomena (coughing and sneezing) that
last extremely short periods of time. Naturally, the human and animal
organisms do not have any specific reflex reactions designed simulta-
neously to eliminate all the disruptions of the hemodynamics occurring
in various sections of the vascular channel under the effect of me-
chanical pressure forces. The organism, therefore, makes use of the
available unconditioned reflexes to restore normal blood circulation.
Breathing under increased pressure produces conditions and reasons
for the use of many of these reflex reactions, but these do not always
agree with one another and frequently overlap; far from eliminating the
hemodynamic disruptions, they occasionally even intensify them thereby
losing their adaptive capacity.
Foremost among the reflexes contributing to the restoration of
blood circulation are those which raise the tonus of the peripheral
vessels and accelerate the cardiac rhythm: from the sinocarotid and
aortal zones in case of a reduction in the arterial pressure within
the large circulation, from the orifice of the caval veins and vessels
of the portal system in the case of rising pressure in them, and from
the lungs as they stretch, etc .
At the same time there are reflexes operating in the opposite di-
rection: from the pulmonary arteries (Shvigka-Parin) and the right heart
(Aviado) in connection with the rising blood pressure in them as well as
the mechanical contraction of the heart by the stretched lungs. These
reflexes produce a bradycardia and a dilatation of the peripheral ves-
sels, particularly of the spleen (Parin). Their unfavorable effect is
manifested mostly in the initial respiration period under excessive
pressure when the hemodynamic conditions in the lesser blood circula-
tion undergo a sudden change which produces the conditions in which these
reflexes are activated; these are followed later by compensatory reac-
tions. But the negative effect of the reflexes from the cardiac and
pulmonary arteries obviously applies also to the entire period of res-
piration under pressure, as the causes producing those reflexes remain
throughout that period.
It is now commonly believed that when breathing under pressure,
bradycardia is a bad prognostic symptom. It is obvious that the already
mentioned reflexes play a fairly important role in producing it. It
329
should be assumed, in addition, that a very frequent pulse is also a bad
prognostic symptom.
In our experiments with dogs involving a systolic frequency of 200
and more per minute, the blood pressure was not always restored to the
initial level. In the initial period, when the beat volume of the left
heart is sharply reduced, tachycardia can be of some use by increasing
the minute volume. But eventually, as the compensatory reactions begin,
the amount of blood entering the heart increases, and the frequent
heart rhythm, as had been established by I. P. Pavlov, not only in-,
creases but frequently decreases the output of the heart, resulting in
a reduced arterial pressure. It is obvious that in these conditions a
moderate increase in the frequency of the cardiac rhythm, which takes
place after 1-2 minutes of respiration under pressure, is better for
the organism; by that time the systolic frequency in the dogs is, as a
rule, reduced from 170-200 to I3O-IUO per minute.
This reaction of a slower cardiac rhythm occurs under the effect
of the parasympathetic nervous system and is adaptive in nature. That
was proved in tests involving the elimination of the parasympathetic
influences on animals with a high and low vagotomy, as well as on
atropinized animals. Those experiments established that for the absolute
majority of the intact dogs and animals with a low vagotomy an excessive
pressure of 300-400 mm of the aqueous column (without the use of external
counterpressure) was quite tolerable, whereas for 50 percent of the dogs
with a high vagotomy it was excessive, and prevented the restoration of
blood circulation function. These dogs were able to tolerate an exces-
sive pressure of only 200-250 mm of the aqueous column. Approximately
similar data were obtained in the test with atropinized animals.
It is apparent, then, that the parasympathetic nerve running through
the vagus nerves and, further, through the efferent cardiac nerves,
moderates the systolic frequency and increases the rest period of the
myocardium, thereby reducing its fatigability. That effect of the vagus
nerves prompted I. P. Pavlov to call them "cardiac rest regulators".
When respiration takes place under increasing pressure, then the load
on the right heart grows heavier because of the difficulty in the lesser
blood circulation; and the role of the vagus nerves as cardiac rest
regulators increases because the right ventricle is less adapted than
the left one to this type of functioning. However, the positive action
of the parasympathetic fibers is not only to reduce the frequency of the
cardiac rhythm and create better conditions for the restoration processes
in the myocardium but also to produce a trophic effect (Smirnov, Kozenko,
and Parin) .
The pressure in the pulmonary arteries increases when respiration
takes place under intrapulmonary pressure due to the resistance to the
blood flow in the lesser blood circulation. This leads to a reflex
opening of the artereovenous anastomoses in the lungs (Boyno-Radzevich,
330
Ryvkind) with the result that the venous blood, bypassing the pulmonary
capillaries, reaches into the pulmonary veins and further into the left
heart. Such a reaction reduces the load on the right ventricle, pro-
tecting it against fatigue. But part of the blood, going through the
bypasses, does not become saturated with oxygen.
It is possible that in terrestrial conditions the mixture of that
part of the blood with the oxygenated blood would not particularly affect
the supply of oxygen to the organism's tissues. At high altitudes, how-
ever, where the partial oxygen pressure in the lungs is known to be
less than in ordinary conditions, and the organism is in a state of
oxygen starvation, the reflex opening of the artereovenous anastomoses
in the lungs will produce unfavorable conditions for the organism's
existence. Thus it may happen that at very high altitudes the effect
of this reaction will be negative rather than positive. This circum-
stance should be borne in mind when designing oxygen apparatus and care
should be taken that the partial oxygen pressure in the lungs when
breathing under excessive pressure at high altitudes is not lower than
under normal conditions (on earth).
The significance of this investigation is that it provides a better
understanding of the physiological mechanisms of the reactions occurring
when special oxygen instruments are used; it also facilitates a proper
evaluation of these reactions and a definition of the stability of the
organism in training flight personnel to breathe under higher pressure.
STUDYING THE NYCTOHEMEKAL RHYTHM OF FUNCTIONS
IN CONDITIONS OF LIMITED MOBILITY
N. Ye. Panferova
The nyctohemeral rhythm of the physiological function is determined
by the formation of a dynamic stereotype of the workday elements and the
rest and sleeping periods. An important prerequisite for formation of
the nyctohemeral rhythm are the elements consolidated in the process of
evolution through heredity- -the typological characteristics of the
nervous system (A. D. Slonira) .
According to Kleytman, Titel 'baum and Gofman, daily body tempera-
ture fluctuations are observable also in newborn babies. But a pro-
nounced nyctohemeral rhythm appears only in the second year after birth.
The nyctohemeral rhythm becomes clearer with increasing age. The authors
associate the appearance of the daily functional fluctuations with the
331
development of a child's activity. In an adult person, the nyctohemeral
rhythm of the physiological function is relatively stable.
A number of authors (Metz, Nielsen, etc.), believe that the capacity
for work- -particularly in the performance of a job that does not require
much energy, such as mental work--is closely associated with the nycto-
hemeral rhythm of the physiological functions. A man's lower capacity
for work at night is, according to Metz, due to the lower body tempera-
ture. The increasing body temperature during the day- produces conditions
for faster biochemical processes in the organism thereby creating better
prerequisites for greater human activity.
Body temperature, pulse frequency, and blood pressure are closely
associated with vigorous activity. K. M. Smirnov, A. D. Slonim, S. 0.
Rutenburg and M. D. Tsybin indicate in their work that the nature of the
daily curve of body temperature and pulse frequency changes with the
specific gravity and physical and mental strain of the work performed
by man.
In conditions of weightlessness, during the space flights, muscular
efforts will apparently be at a minimum. It would therefore be interest-
ing to determine the changes that may be produced by a maximum possible
limitation of muscular work and movements on the nyctohemeral rhythm of
body temperature, pulse frequency, respiration, and blood pressure.
The experiments involved in the study of limited mobility were
carried out in two series using 11 people, four in the first series and
seven in the second: in the first series, test subjects were kept flat
on their backs for 2 to 10 days in special armchairs in a position con-
ducive to a maximum muscular relaxation; in the second series, they
were kept for 1.5-11 -5 days in a lying position in water. Body tempera-
ture, pulse frequency, and blood pressure were measured every 2 hours by
members of special teams on duty.
During those tests, the daily conditions were maintained as close
to the usual conditions as possible, with the exception of motor activity.
During the day, the test subject was, as a rule awake, and the changes
made during those periods did not require any motor activity. The test
subject listened to radio transmission, music, literature readings, and
took an active part in conversations . He took a nap whenever he felt like
it. At night he was kept in semidarkness, in conditions conducive to
sleep.
Maximum immobility was an indispensable condition of all the tests.
With the exception of the sleeping period, the body temperature was
taken under the tongue every 2 hours around the clock, the pulse frequency
was counted, and the respiration checked; the arterial pressure was also
measured in the test subjects of the first series.
332
The investigations revealed that the nyctohemeral rhythm of the
functions under study, particularly the body temperature, changes in most
cases of limited mobility. The changes of the nyctohemeral rhythm are
more pronounced when the test subjects are kept in water.
The typical daily changes of the pulse frequency, respiration,
maximum and minimum blood pressure and body temperature could be traced
in the case of test subjects G. and A. who were kept for 8.5 and 10. 5
days in terrestrial conditions of limited mobility, and test subject S.
who was kept in conditions of aqueous hypodynamia for 11. 5 days.
The daily pulse frequency fluctuations during the first days of
the hypodynamia were within the range of 10-15 beats per minute; the
respiration frequency was 5-8 respirations per minute; and the maximum
and minimum arterial pressure was within the range of 10-15 mm Hg. The
changes of the daily fluctuations of these functions in conditions of
prolonged limited mobility were manifested as a tendency to obliteration,
that is, a reduction in the amplitude of these fluctuations.
In the first 2 days the configuration of the daily curves of the
body temperature was, as a rule, similar to that described by Mosso.
In the following days the curves revealed a sharp change. The daily
curves of the body temperature were characterized by a rapid rise to
36.9-37.I by 10-1200 hours (on the sixth day in the case of test sub-
ject G., and the seventh and ninth days in the case of A.); they re-
mained at that level until 20-2200 hours within a fluctuation range of
0.1-0.2°, and were then followed by a gradual drop or new rise. In
subject A., for example, the body temperature rose again to 37-1° by
2^00 hours.
It is interesting to point out that the configuration of the curves
during the hypodynamia was not stable, the body temperature curves of
the same test subject revealing sharp changes on different days.
In test subject G., the body temperature fluctuated at the 37. 1-
36.9 level on the sixth day of the hypodynamia from 10 to 2200 hours.
On the seventh day the body temperature rapidly rose to 37. 1° by ll|00
hours, then dropped to 36. 4° by 1600 hours, remained at that level for
6 hours and began to rise again by 2400 hours .
After 8 days in water, the daily curve of the body temperature fluc-
tuation in test subject S. was distorted. If in the first day of the
hypodynamia the highest body temperature noted at 1800 hours was 37. 2°,
the lowest body temperature recorded at 1800 hours on the ninth day was
36. 2°. On the tenth day there were practically no daily fluctuations
in subject S. between 8 and 2000 hours, and his body temperature re-
maned at 36. 5- 36. 6°, and only by 2200 hours did his body temperature
rise to 37. 0°.
333
The information obtained in this project justifies the conclusion
that vigorous muscular activity is an important component required for
maintenance of a daily functional stereotype. A limitation of human
motor activity results in a disruption and change of the adaptive re-
actions developed in the process of the phylo- and ontogenesis. Ob-
viously, a disruption of these adaptive reactions is not a matter of
indifference to the organism.
The maintenance of the nyctohemeral rhythm of the functional
fluctuations is apparently an important ingredient in the preservation
of a person's capacity to work. The development of a pattern of work
and rest for professions characterized by limited mobility should
therefore provide for measures designed to maintain a normal nycto-
hemeral rhythm.
THE ACHIEVEMENTS AND GOALS OF SPACE MEDICINE
V. V. Parin
(The text of this report has not been submitted.)
SOME STRUCTURAL PRINCIPLES OF FLIGHT CONTROL
AND NAVIGATION SYSTEMS
Yu. A. Petrov
The history of the development of instruments installed in planes
for the use of pilots in flight shows that the evolution of these in-
struments has been characterized by an increasing scope of information
received by the pilot, and a higher degree of information reliability.
In visual flight, such instruments are required as extensions of
the human sense organs . They enable the pilot to make a thorough
analysis of the range of the processes under his control which cannot
ordinarily be perceived. This applies to the speed and altitude of
flight and temperature control (oil, cylinder heads, exhaust gases,
turbine operations, and other flight parameters). In night flight,
in cloudy weather, and in fog the instruments are the only source of
reliable information on the position of the plane in space and its progress.
;\
33^
Now that automatic and semiautomatic flight control systems have
come to the aid of the pilot on a large scale, the very approach to
flight instruments is undergoing a change. First of all, it is possible
to prevent the pilot's attention from being over-taxed by secondary in-
formation on the performance of the power plant (motor or engine). The
pilot's attention should be focused only on the emergency features of
the motor operation, that is, when the failure of the automatic facili-
ties calls for other measures designed to correct an emergency situa-
tion. It is also becoming possible to relieve the pilot's attention
of all other auxiliary information. The pilot should always be free to
concentrate on the following aspects of the flight :
(a) Where and in what position is the plane.
(b) In what stage is the implementation of the preset flight program.
(c) Actual flying conditions as compared with the prescribed ones.
(d) Performance of the apparatus installed in the plane.
In order for the pilot's perceptive process to be fairly simple and
reliable, the cockpit instruments must meet a number of requirements in
respect to nomenclature, general shape and appearance, rational sizes,
combinations of certain groups of instruments, and overall design.
From the point of view of nomenclature, the various problems of
flight control and the required information on a number of auxiliary or
short-duration processes call for an excessively large nomenclature of
instrument indicators. Various indicators should be designed to control
the spatial position of the plane, fly the plane at a preselected alti-
tude and an optimal speed in the desired direction, and control the
performance of the power installation and auxiliary devices. It would
be expedient in this connection to supply the pilot with the part of
the information required for the implementation of a particular stage of
the flight program. In addition, some instruments, especially of the
auxiliary type, should be connected only when the parameter (process)
they control shows a dangerous deviation from the normal course.
That the instrument panel, particularly a single instrument,
should be characterized by a single indication principle becomes obvious
at first glance. The general aspect of this principle is indisputable.
A mixture of principles-- "from the plane" and "into the plane" on the same
panel--has an adverse effect on the pilot's orientation in the events
under control. In the solution of certain concrete instrument- indicator
problems, however, certain departures from this principle are not only
possible but also necessary. Such a necessity was exemplified by the
change from the gyro horizon AGK-V7B and AGI-1. Although it is easier
to read the gyro horizon AGK-U7B than the gyro horizon AGI-1, the latter
335
has a definite advantage in the range of its action. While the AGK-VfB
is limited to a very narrow range of permissible lateral and longitudinal
pitch, the AGI-1 is subject to no such limitations.
A study of published information and experimental tests appears to
favor the following system of instruments. All indicators are divided
into two basic groups :
1. Information indicators. Their purpose is to "extend" and
strengthen the sense organs in such a way as to make it possible for the
pilot to control the conditions and nature of the flight, as well as
the performance of the power plant and the auxiliary apparatus .
2. The command indicators. The purpose of these indicators is to
alert the pilot to his next move. Such prompting may be concrete or
general. Certain information indicators are of a command nature. For
example, when the exhaust gas temperature reaches a high point, the
pilot knows that he must reduce the gas, but this is not a strictly
command instrument because the latter should be equipped with an arrow
indicating not 900° but a command inscription saying "remove gas".
The information indicators include: (a) abstract quantitative in-
dicators (altitude, speed, Mach number, etc.); (b) visual indicators
characterizing primarily the spatial position of the plane; this in-
cludes banking, pitching, and direction characteristics; (c) signaling
devices: strictly speaking, signaling can be attention attracting (if a
light flashes near the instrument or the apparatus), warning (when a
light flashes indicating something is wrong), directing (if the signal
directs the pilot's attention to a concrete group of instruments or a
certain lever), and informing (in which case the signal informs of an
event that has already occurred, as for example "no oil"). There are
sound and light signals, the latter appearing in the form of indiffer-
ent bulbs or illuminated inscriptions. The signaling devices are char-
acterized by the following qualities: (a) attention-attracting elements,
and (b) information on a particular event or condition.
The signaling devices may also be of a commanding type. For ex-
ample, as the plane is about to land there appears an inscription saying
"lower landing gear".
The command indicators, unlike the first group of information indi-
cators, are not primarily designed to enhance the pilot's analytical
possibilities in flight. They should be made in the form of zero-
instrument indices, or devices indicating scratch marks or, finally, in
the form of command inscriptions, already mentioned.
There is a direct relationship between the urgency of the problems
of engineering psychology and the rate of development of aviation technolgy.
336
PATHOMORPHOLOGICAL CHANGES INDUCED IN ANIMALS BY ROTATING THEM
AROUND AXES RUNNING THROUGH THE PELVIC-CARDIAC-CEPHALIC REGION
V. G. Petrukhin
Very little is known about the pathomorphological changes produced
in the organs by various types of acceleration occurring in aviation
practices. The purpose of this investigation is to define certain changes
of the internal organs in dogs subjected to rotation around an axis
running through various sections of the body. A study of such over-
loads is important for the development of prophylactic measures, es-
pecially when bailing out in emergencies.
Our investigations involved k-7 dogs, of which kl were subjected to
the effect of overloads varying in direction, magnitude, and duration,
on special rotating stands. The tests and physiological investigations
were carried out by S. S. Markaryan, E. V. Marukhanyan and I. A. Tsvetkov.
In the first series of tests the rotation axis ran through the pelvic
region, with a body tilt angle toward the axis varying from 20 to 90°.
The animals were subjected to single and repeated effects each of which
lasted from h to 20 minutes, and the overloads created at the head level
amounted from 2.5 to Ik- (22 dogs).
In the second series, the rotation axis was perpendicular to the
body and ran through the cephalic region. The animals were subjected
to a single effect amounting to from 6 to 17.2 and lasting 3-20 minutes
(5 dogs).
In the third series, the rotation axis ran through the cardiac
region, thereby creating an overload at the head level amounting to
from 6 to 14 and lasting 7-23 minutes (5 dogs).
In the fourth series, the animals were rotated around an axis
running through the pelvic region for k seconds at a maximum angular
acceleration from 180 to 320, and a trip-out of 200-J+00°/sec2; the over-
load at the head level was from 9 to 14 . The rotation time at a maxi-
mum speed did not exceed 2 seconds (angular accelerations; 9 dogs).
In 23 cases, the animals died during the test. Eighteen of the
animals were killed at various periods ranging from 30 minutes to 12
days after the end of the test. Six dogs were examined for control
purposes. All the dead animals were subjected to a careful pathoanatom-
ical investigation followed by a histological processing of organ
specimens, according to the commonly accepted methods.
The morphological examinations revealed that the lengthy radial
accelerations simulated on a rotating stand, regardless of the location
337
of the rotation axis (the pelvic, cardiac or cephalic region) and the
body tilt angle toward the rotation axis, produce considerable changes in
the organism when the overload exceeds 2-5 and lasts 20 minutes. If the
overload increases more than sixfold, the animals die during the test in
most cases . The dogs were found to tolerate the rotation-produced over-
load more easily when the rotation axis ran through the cephalic region
than through the pelvic or cardiac region. The difference between the
overloads (under an effect lasting 20 minutes) was 1.5-2 and 2-3, re-
spectively. In the case of shorter effect periods but great overloads,
this difference is considerably smaller. The animals can withstand
greater accelerations by almost 2-2.5 overloads when the body is in-
clined toward the rotation axis at an angle of 20° as compared to 90° •
The difference in the tolerance of overloads by individual dogs in all
directions did not exceed 1.5-2. The maximum tolerance of the dogs
under the effect of angular accelerations was the accelerations exceed-
ing J+8o°/sec2 at a rotation with a maximum overload lasting over 2 sec-
onds (not counting the time used in acceleration and deceleration). Al-
though the accelerations in the different tests were in opposite direc-
tions, the pathomorphological picture of the changes was almost identical.
Whenever the animals died during the tests, or were killed in the
first 30 minutes after completion, their right heart cavities, caval
veins, and pulmonary arteries were found to be sharply dilated with
blood, and there was a plethora of the pia mater of the liver near the
radix pulmonis. The latter also revealed hemorrhages and atelectasis
on the dorsal and diaphragmatic surfaces.
The only difference was as follows : overloads in the head produced
hemorrhages in the mucous membranes of the eyes, in the accessory cranial
cavities, and pia mater; the pelvic organs were anemic. A shift of the
overloads to the pelvis reversed the picture. The hemorrhages were more
pronounced in the case of angular accelerations.
There was no indication of blood redistribution in the animals
killed a day or more after the test. The hemorrhages were gradually re-
sorbed. A microscopic examination failed to disclose any disruptions
specific to accelerations in a certain direction.
The changes in the brain began with perivascular adema and hemor-
rhages (the latter were more frequent under the effect of angular ac-
celerations but very rare in positive accelerations). This was followed
by an edema around the ganglion cells and nerve fibers. Dystrophic
processes (of the ischemic type) appeared at the same time in the gan-
glion cells, reached their maximum by the second day, and lasted until
the animals died. There was an increase in the number of gliosis ele-
ments around the changed ganglion cells and capillaries between the
first and seventh day.
338
Anemia, an edema of the connective tissue layers, small hemorrhages,
and a reduced glycogen content in the muscular fibers were found in the
hearts of the animals that had died during the test. The animals killed
3O minutes and more after the test also revealed symptoms of albuminous
dystrophy (eosinophilia, fuchsinophil granule, homogenization, and the
loss of striation), less often fatty dystrophy and on still rarer occa-
sions the death of individual muscle fibers. In the course of time the
glycogen was gradually restored, the dystrophy disappeared, and between
the third and seventh day the heart returned to normal (with the excep-
tion of cases accompanied by the death of muscle fibers ) .
The lungs of the animals that died or were killed 30 minutes after
the test revealed wide open arteriovenous anastomoses, hemorrhages,
atelectases, and perivascular edema. The animals killed later under
similar conditions frequently revealed catarrhal pneumonia.
A granular and vacuolar dystrophy, changing to a fatty dystrophy
a day later, developed in the liver immediately after the capillaries
had become filled with blood; the connective tissue layers were af-
fected by edema and occasionally also by a hemorrhage.
Symptoms of a reduced quantity of lymphoid elements in the follicles
were found in the spleen, as well as a hyperplasia of the reticular cells
and an accumulation of hemosiderin in the pulp. A larger quantity of the
latter was found also in the Kupffer cells of the liver.
In addition to a turbid swelling and vacuolization of the epithelium
of the winding canals, the kidneys occasionally revealed a vacuolization
of the endothelium of the glomeruli and a spasm of the "lead-in" arteries.
A reduced quantity of lypoids in the cortical layer was found in
the adrenal glands of the animals killed a day after the test.
Thrombi were found in some cases in the pulmonary, liver and peri-
cardium veins .
The disturbance of the blood circulation in the other organs ap-
peared in the form of edemas, venous stasis, and occasionally also
hemorrhages.
Repeated acceleration effects failed to reveal any marked increase
in the animals' resistance to overloads. An investigation of the animals
found the consequences of former sharp changes, the number and quality
of which depended primarily on the frequency of the overloads and the
time that had since elapsed.
Hydrocephalus was found in 2 of the 8 dogs, thrombosis of the right
auricle and atrium cordis in 2 others, and foci of bronchopneumonia or
339
small pneumo sclerotic foci in all of them (depending on the time they
had been killed); there was a mild hypertrophy of the ventricles and
occasional foci of micromyomalacia with symptoms of cicatrization; small
rarefaction foci were found in the brain, and symptoms of a chronic stasis
in the liver; organized and rechanneled thrombi were observed in the
pulmonary, cardiac, and liver vessels.
It should be emphasized that hemorrhages in the mucous membranes of
the nose and eyes represent a dangerous symptom. Our observations of
all the animals affected by such hemorrhages revealed considerable
changes in all the organs, and extensive hemorrhages in the lungs.
It should be assumed, on the basis of the above, that the chief
reason for the morphological disruptions produced by prolonged accel-
erations is the disruption of the blood circulation in the organism
accompanied by a blood stasis in the lesser circulation and the opening
of arteriovenous anastomoses in the lungs . Inadequately aerated blood
enters the left heart, a hypoxia of the myocardium and the brain develops,
and the combination of hypoxia with higher pressure in the vessels in-
creases their porosity and develops edema and hemorrhages. The results
of hypoxia, venous stasis, and edema are dystrophic and necrobiotic
processes in the cells of the brain, myocardium, liver, and other or-
gans. The hemorrhages and edema contribute to the inflammatory proc-
esses in the lungs. The disruption of the fluid circulation in the brain
plays an important part in the genesis of the changes.
The main reason for the injuries sustained under the effect of
angular acceleration is apparently the sharp "striking" increase in the
venous pressure and the sharp displacement of the organs. The effect of
disrupted hemodynamics in these cases probably plays a secondary part.
THE PATHOMORPHOLOGY OF TRANSVERSE OVERLOADS
V. G. Petrukhin and M. M. Sokolova
Acceleration produces the only effect of its kind that so rapidly
and crudely disrupts and distorts the blood circulation and, naturally,
will produce morphological changes in the organism when that effect is
powerful enough. However, morphological investigations, especially those
concerned with the effect of transverse acceleration, have been prac-
tically nonexistent.
This project summarizes information on the pathomorphological changes
in 52 dogs and I3 monkeys subjected to the effects of transverse
3^0
accelerations. Seven dogs and 1 monkey were examined for control pur-
poses. The tests in a centrifuge and the physiological investigations
were carried out by A. R. Kotovskaya, S. F. Simpura, A. V. Yeremin and
V . A . Arkhangel ' skiy .
All the tests may be divided into four series. In the first series,
the dogs were subjected to the effect of an eightfold overload for 3
minutes in the chest-back direction; in the second, to a twelvefold
overload lasting one minute; in the third, to a twelvefold overload for
three minutes; and in the fourth, the female monkeys were subjected to a
twelvefold overload lasting from 3 to 5 minutes (depending on the elec-
trocardiographic changes) with the back of the armchair inclined at an
angle of 20 to k^° toward the horizontal. After the tests all the ani-
mals were sacrificed by ether; some immediately, other 1 hour later,
and 1, 3, 7, 15, 3O and 60 days later.
The results of the morphological investigations revealed that the
nature of the changes in the animals ' organs in all four series of tests
were identical. But the extent of the affection was somewhat different,
the animals of the second and third series revealing more extensive
lesions.
An investigation of the animals killed less than an hour after the
effect showed that the right heart cavities, the vena cava, the pul-
monary arteries, and liver veins were overfilled with blood. The
diaphragmatic lobes of the lungs on the dorsal side were also overfilled
with blood. Small or large hemorrhages were found in the same lobes
closer to the radix, as well as in the central lobe of the right lung
and cardiac portion of the left lung in most of the animals under the
pleura. Hemorrhages were observed also deep in the tissue. Brain,
liver, and kidneys were plethoric; myocardium was flaccid and anemic.
Disrupted blood circulation was not observed in the animals killed
8 days and longer after the experiment. Macroscopic changes were found
only in the lungs .
A microscopic examination of the brain 1 hour after the effect re-
vealed a slight edema of the meninx and substantia medullaris. Dystrophic
processes (of the ischemic type) appeared 1 day later in the ganglion cells
(chromatolysis, swelling, and vacuolization) extending to the formation
of tissue cells. These changes reached their maximum by the third day,
followed a little later, by proliferative processes of the gliosis cells,
the latter frequently concentrating around the damaged ganglion cells
or certain capillaries. In 7 to 15 days, the ganglion cells of the cortex
were back to their usual structure. In some cases, the symptoms of
glia proliferation lasted 30 to 60 days.
Eosinophilia of the muscular fibers (occasionally with the loss of
striation) and a fuchsinophil granule in the protoplasm were observed in
3U1
the heart 1 hour after the test, in addition to the anemia and the edema
of the connective tissues. By the end of the day the edema diminished,
and symptoms of albuminous dystrophy increased. After the third day,
the dystrophic processes gradually diminished, and by the 15th day the
myocardium returned to its usual condition. In some animals of the third
and, particularly, the fourth series of tests, fatty dystrophy and small
foci of micromyomalacia were found in the myocardium of the left ventricle.
A histochemical test showed a reduced glycogen content in the myocardium
of the animals killed immediately after the effect. This pattern was
particularly prominent in the animals of the fourth series of tests
(monkeys). By the end of the day the glycogen content in the myogenic
fibers of the heart was higher than usual in the animals of the first
and second series; in the animals of the fourth series of tests, the
superregeneration phase occurred later, by the third day.
A pronounced plethora, particularly in the root zone and closer to
the dorsal side, was observed in the lungs of all the animals 1 hour
after the test. The arteriovenous anastomoses were wide open, and most
of the animals revealed hemorrhages and edemas. The latter, as a rule,
developed into an inflammatory process 1 to 3 days later. By the seventh
day most of the hemorrhages were resorbed, and the severe inflammatory
processes abated. In only half of the cases did symptoms of a produc-
tive reaction develop in the foci of the remaining inflammation. Fifteen
to 30 days later, infiltrates from the lymphoid cells and histiocytes and
a (focal) intumescence of the interalveolar septa were discovered near
the bronchi in a few animals.
By the end of the day, a granular and occasionally vacuolar dystrophy
developed in the liver against the background of a considerable venous
stasis. Between the third and seventh day, however, the liver regained
its normal structure. An accumulation of hemosiderin was observed in
the Kuppfer cells during these periods.
The changes in the kidneys 1 hour after the effect were characterized
by a considerable plethora of the tissue. A granular and occasionally a
vacuolar dystrophy eventually developed in the epithelium of the winding
canals. An increase in the cells (of the histiocytic type) around the
"lead-in" arteries was observed in some cases between the 7th and 15th
day. No changes were noted in the kidneys by the 30th day.
A decrease in the number of lipoids was observed in the substantia
corticalis of the adrenal glands 1 day after the experiment. At the same
time, there was a decrease in the number of lymphoid cells in the spleen
follicles .
The above-described pathomorphological picture of the brain and
myocardium affection is by its nature similar to the changes produced
by hypoxia. The transverse overloads apparently disrupt the blood supply
3^2
to the brain and myocardium, while the wide open arteriovenous anastomoses
in the lungs, the venous stasis and the edemas around the vessels con-
tribute to the genesis of hypoxia in these organs.
The changes in the lungs can probably be explained by the fact that
the blood, because of its mobility (displacement), flows to the dorsal
departments under the effect of acceleration. In view of the "increasing
weight" of the fluid column, however, the right ventricle is unable to
"push" the blood through the entire lung tissue, thereby producing the
conditions for a stasis in the areas near the roots. A rising blood
pressure in the pulmonary vessels results in the transudation of the
plasma and erythrocytes and the breakup of the capillaries.. Eventually
the resorption of the edemas and hemorrhages produces an inflammatory
process similar in type to traumatic pneumonia.
In summation, accelerations produce in animals a large number of
morphological changes, mostly reversible, in the cerebral cortex, heart,
lungs, liver and other organs associated primarily with the disruption
of the blood circulation in the entire organism.
SOME PROBLEMS OF THE HUMAN PERSONALITY IN AERONAUTICS,
AVIATION AND ASTRONAUTICS
K. K. Platonov
As a historically new and rapidly changing type of human activity
in very specific conditions, flight has revealed certain patterns which
are at times less noticeable in other cases of interaction between the
human being and the surrounding medium. It also reveals more clearly
the personal attitudes of the human being and his personal qualities.
Aeronautics, aviation, and astronautics, since their genesis, have
attracted the attention of various scientists, and have produced con-
flicting opinions concerning personality and its role in flight. The
problem raised in the heading of the report, extends beyond aviation
medicine, and its significance goes far beyond historic interest.
The prerequisites for this type of a review of the problem are :
the publications of recent years on the history of Russian aviation
medicine and psychology; the common point of view achieved at the All-
Union Conference in May 1962 on the philosophical aspects of the physi-
ology of the higher nervous system and psychology, and the achievements
in aviation and space medicine discussed at that conference. It is par-
ticularly important to discuss the problem raised in the heading of the
3^3
report in the light of the resolutions adopted by the June Plenary Ses-
sion of the Central Committee of the CPSU of this year.
We shall cast a glance at the past because, as is known, there is no
theory without history, and the past yields a lesson for the future.
Flying in a balloon, man was relatively inactive. The progressive
tendency of the first aeronauts (S. L. L'vov (1803) and Ya. D. Zakharov
(l804)) prompted them to overcome the sensational glory of "fearless-
ness" on the part of aeronauts. Their attention was rightly directed to
the study of the gnostic qualities of the human being. M. A. Rykachev
(1882), who no longer pursued that goal, was the first to provide a
fairly substantial list of qualities required by an aeronaut- -a brief
description of professional skill which still applies to pilots as well
as astronauts. Elaborating a bit, it may be said that aeronautics
(which is again on the agenda^) presented a number of basic requirements
in the field of gnostic qualities; aviation superimposed psychomotor
requirements on them, and astronautics added both of the requirements
to the intellectual, volitional, and moral qualities of the personality.
According to S. P. Munt (1897)? his first investigations in a
balloon were designed to establish the necessary expert requirements and
prevent accidents. Those were, indeed, complicated physiological and
psychological requirements, for it was only natural that at that scien-
tific level the study of the human personality coincided with the psy-
chological study of man in flight.
The aviation age was started in accordance with N. Ye. Zhukovskiy's
(1893) classical thesis that "Man in flight will be propelled not by
his muscles but by his mind". The first articles requiring the legali-
zation of an expertise for pilots (S. A. Beknev, 1911 and L. I. Shif,
1912) justly advocated a medical and psychological selection. The be-
ginning of medical aviation expertise (19H) coincides with the first
experimental psychological examination of the aviators in the world,
conducted by V. V. Abramov in V. M. Bekhterev's clinic as part of a
study of the higher creative features of the human personality.
An analysis of that period shows that the study of man in flight be-
gan as a combined study of the human being as an organism and a personal-
ity. Two distinct approaches (both are still in force) were soon made
to the to the psyche of the flier: personal and functional, both of which
are combined with the mechanistic approach. These approaches were soon
clearly manifested in P. N. Nesterov's fight for a conscious piloting
of a plane and against the idea of instinctive piloting which had been
borrowed from abroad.
The discussions at the Third All-Russian aeronautical congress
(8-I3 April 191U) also reflected these two lines. At that congress, the
3W
progressive idea, which is still in force, was not only a defense of the
development of flying capacities (N. A. Yatsuk), but also a defense of
the concept of flying capacities as personal qualities, not only as flying
habits (A. F. Prussis). It is interesting to point out that a similar
discussion, which should be viewed from these same positions, was re-
cently repeated (December 1959-February i960) in the newspaper Sovetskaya
Aviatsiya (Soviet Aviation) under a subtitle "Talent or effort?".
The discussion begun in 191^ grew sharper in the first half of the
twenties when the first point of view was defended by S. Ye. Mints,
who considered the synthetic methods of examining the military student
for selection purposes only as the first stage of the following dynamic
study of the "students psychology". The second point of view was de-
fended by the psychological technicians--isolated from psychology, who
replaced the analytical methods of investigating the military students- -
first used by A. P. Nechayev, by testing. The latter approach to the
human personality in the second half of the twenties and early thirties
became official. But the struggle against it, conducted from correct
positions, did not come to an end but took the form of a struggle for
the psychohygienic trend (N. A. Molodtsov, S. I. Subbotnik, S. P. Ron-
chevskiy and, eventually, I. V. Kontorovich) . The views of N. A.
Molodtsov, the founder of Soviet aviation medicine expertise, have been
unjustly forgotten. His idea of combining as much as possible the psy-
chological study of the personality in the course of selection with the
related study of the psychohygienic performance now deserves special
attention. It is in this particular direction, but in combination with
the contemporary views on the formation of the pilot's individual charac-
teristics and flying capacity, that work should be further developed
into a definite system.
The dissatisfaction with the psychotechnical investigations and
the protest against them, in addition to healthy criticism, took the
form of a biological evaluation of the flyer's personality. Those
biological views, which swept across aviation medicine in three waves,
delayed the psychological investigations and the publication of the
projects already completed, but most of all they interfered with the
development of the proper methods and positions required in the investi-
gation of the flyer's personality.
Those waves had, of course, originated outside the field of aviation.
But in aviation they took the form of a fight against psychology, char-
acterized by three typical features: first, it was concentrated primarily
in the area of individual psychology; second, the purpose of the struggle
was not to improve the study of individual psychology but to put an end
to it; third, this struggle was protracted in nature and continued even
after it had already been completed in other areas.
The first wave of the twenties was determined by a wide prevalence
of reflexological views among the aviation doctors, with N. M. Dobrotvorskiy
3^5
as the proponent of such views . This situation continued in aviation
even after the "reflexological discussion" (193O-I93I).
The second wave was characterized by an erroneous understanding of
the resolution adopted by the Central Committee of the All-Russian Com-
munist Party (bolsheviks) "On the Pedological Distortions in the System
of the People's Commissariat of Education" in I936. Instead of the ex-
pected enhancement of the psychological effort, the result of this wave
in aviation was the administrative suppression of the psychological in-
vestigations and the study of the personality problem.
The third wave in this biology trend was characterized by the mis-
understanding of the meaning of the "Pavlov session" (I950) and an
ignoring of the thesis with which K. M. Bykov used to begin his lecture:
medicine, as the science of man, should also be based on biology and
psychology.
Despite the fact that the Ail-Union Conference on the philosophical
aspects of the physiology of the higher nervous system and of psychology
(May, I962) and the following joint resolution of the Presidiums of the
USSR Academy of Sciences, USSR Academy of Medical Sciences and the RSFSR
Academy of Pedagogical Sciences, called attention to the struggle against
the biological trend and the negative attitude to psychology as its
manifestation, the "biologization" trend in aviation medicine has not
completely abated to this day.
The struggle between the progressive and "biological" views of the
flyer's personality was manifested also in the history of the individual
approach to the aviation medicine expertise. The progressive side in this
case was represented by the struggle for higher personal and psychological
qualities of the flyer, as part of the flight and medical qualifications,
to be included in the expertise along with the results of the experimental
psychological investigations. Here the progressive feature was the ef-
fort made in the theory of the individual approach to the expertise in
aviation medicine (N. A. Molodtsov, G. R. Grayfer, Ya. F. Samter, etc.).
The opposition to this, as a rule, leaned heavily on the biological views.
It was not accidental that not a single project was carried on in this
field during the last "biological" trend. The theory of the individual
approach in this expertise, which is part of the theory of personality,
is now practically dead. And yet it is this theory that is so urgently
required not only for an expertise for flight personnel; the time is not
far off when it will be required also for astronauts .
The June Plenary session of the Central Committee of the CPSU, deal-
ing with ideological problems, promptly raised the personality problem
before the representatives of various sciences. Lying in the area between
aviation psychology and aviation medicine are a number of important prac-
tical problems of the personality which call for an urgent solution.
3h6
In addition to the already discussed problems, these include pri-
marily a study of the social aspects of personality (orientation and
moral qualities) and their role in the general structure of the person-
ality as well as in the compensation for various defects of other aspects
and somatic defects. Included here is the personality criterion for the
selection of military pilots, which is unjustifiably treated separately
from the prediction of the training course. Included here also is the
study of personality reactions to unfavorable flight factors, particularly,
hypoxia and overloads. It is impossible to resolve all these problems
without regard to motivation which (in the case of hypoxia) has just
been initiated by G. D. Naroditskaya (19^9)- The problem of flight
fatigue cannot be completely resolved without taking motivation and
personality compensation into account (Ye. A. Derevyanko). Still to be
thoroughly studied is the problem of personality relations as well as
relations among personalities. Herein lies the psychological basis for
the selection of flight crews. Some theoretical experimental pre-
requisites for the successful solution of this very important problem
are already available, but engineering psychology in aviation has only
begun to develop its own dynamic aspect and to deal with the personality
aspects, particularly the aesthetic requirements, of crew selection.
The complex study of man in flight, not only as an organism but also
as a personality, which took shape spontaneously under the effect of prac-
tical requirements and was delayed by three trends of "biological" views,
must become a theoretically substantiated program for the further develop-
ment of aviation and space medicine . The art of flying must be studied
in combination with the personality. Developing along the lines of
aviation medicine (and particularly in close association with aviation
medicine expertise), aviation psychology has already laid a fairly solid
foundation and, basing its efforts on the physiology of the higher
nervous system, should proceed to the completion of its superstructure,
the theory of personality and personality relations. The implementation
of this task is not an easy problem; it is considerably easier to study
the separate functions. But the implementation of this very complex
requirement will save aviation medicine from a recurrence of the "bio-
logizing" errors.
3^7
EVALUATING THE EFFECTIVENESS OF THE EXPERIMENTAL METHODS
USED IN THE PSYCHOLOGICAL SELECTION OF AVIATION CADETS
B. L. Pokrovskiy, T. I. Zhukova and V. P. Zukhar *
One of. the important problems in the psychological selection of
aviation cadets is to evaluate the effectiveness of individual methods.
The major requirements for selection techniques are predictability and
reliability. Predictability is characterized by the correlation of the
methodological data with the successful mastery of the art of flying.
A close correlation can be achieved when the methods reveal the indi-
vidual psychological characteristics of the personality which are very
important for the flying profession. Reliability is characterized by
the constancy of the results achieved on repeated application of a
given method. It means that the investigation results are not acci-
dental but reflect certain definite patterns .
We verified predictability by comparing the investigation results
with a given flight progress. This was done by two methods. In some
cases the experimental data were compared with the psychological char-
acteristics revealed in the course of flight training. Thus, the methods
designed to study particular aspects of attention were compared with the
quality of the attention shown in the flights : its distribution, the
ability to combine various activities and watch several instruments
simultaneously, discretion, etc. The evaluation of the predictability
of the tests designed to study the characteristics of the development
of new habits and the changes of old ones took into account the speed
and ease with which the flying habits were acquired (the number of test
and control flights, the mastery of new types of flights), the extent to
which these habits have been mastered, the effect of interruptions on
piloting, typical errors, etc.
In other cases it was found more expedient to compare the investi-
gation results with the general flying progress.
The investigations revealed considerable differences in the effec-
tiveness of the methods. Some of them were characterized by a fairly
high degree of predictability; others were completely unsuccessful. We
shall cite the example of a group of cadets examined during their admis-
sion to school in 1953. Eight different tests were used: adding and
switch manipulating, "folium- vibrometer", finding numbers and manipu-
lating switches, distributing numbers, and entangled lines. An analysis
revealed that the test results appeared in the above-listed order, in
point of effectiveness. The shortcomings in the psychological qualities
of the persons successfully completing their methodical assignments of
"adding and switch manipulating: and "finding numbers" were less than
one-half than among the persons completing those assignments unsatis-
factorily. At the same time, the shortcomings of the attention in flight
3^8
were equally frequent (in UO percent of the cases) among the cadets who
rated an excellent and good grade in the completion of the "entangled
lines" tests, and those who put in a poor performance. The distribution
of numbers produced similar information.
A comparison of the results of the experimental psychological in-
vestigations with the general flying progress shows the same general
picture. The data on a group of cadets from one of the flying schools
may serve as an example. They were divided into two groups: those whose
performance of a task by a particular group of methods was rated excel-
lent and good, and those with an average and poor rating. The per-
centage of the slow cadets who should not have been admitted to school
was determined in each group.
The figures are cited in the table (see page 3^9). That table shows
that the cadets performing their tasks successfully by the first three
methods include approximately half as many poor students as those com-
pleting their tasks with an average and poor rating. The "scales esti-
mating" tests was found to be absolutely useless.
A comparison between the groups of cadets completing their experi-
mental task with a consistent "excellent" rating, and those with a con-
sistently "poor" rating produces still more contrasting results. Thus,
among the cadets completing their addition and switching test with an
"excellent" rating, the number of poor students was h."J times smaller
than among the poor performers; the number was 3.^ times smaller in the
compass-reading test, etc.
The reliability of the results was checked in repeated investiga-
tions of the group of cadets by the same methods and in practically the
same conditions after one year (l959> i960) . The differences between
the evaluations of their performance in the first and second time were
calculated. The correction-making tests, numbers finding, addition and
switching operations, and compass reading revealed a fairly high perform-
ance similarity in the first and second tests amounting respectively to
82, 86, 93 and 75 percent. The reliability of the "tube tachistoscope"
and "scale estimating" tests was found to be inadequate.
A special checkup on the effectiveness of the methods we had adopted
for practical psychological selection purposes revealed that while the
investigation results obtained by means of an entire complex of methods
correlated with the quality of the flying progress (with a 99 percent
probability), the probable correlation based on individual methods was
always below 95 percent .
It follows from the above that the results of the investigation by
the same methods carried out at different schools and compared in dif-
ferent ways reveal a systematic recurrence. The cadets performing their
3^9
Percentage of students showing poor
flying progress among those completing
the prescribed assignments
No . Methods
Excellent and Satisfactory and Ratio
good poor
1 Addition and switch manipu-
lation 21
2 Correction-making test 22
3 Number finding and switch
manipulation 25
k Compass reading 2k
5 Finding numbers 31
6 Tube tachistoscope 27
7 Scales estimating 3^
tasks by the most predictable methods contain about half as many slow
students as the poor performers. Such an analysis makes it possible to
choose the most expedient methods for psychological selection purposes.
But such a selection can be made only by the use of a complex of methods
designed to investigate the characteristics of the various psychic pro-
cesses and the personality as well as a combination of both of them.
hi
1:2.2
k6
1:2.1
51
1:2.0
ko
1:1.7
k6
1:1.5
kl
1:1.5
31
1:0.9
SOME REASONS FOR ERRORS MADE BY THE PILOTS IN
INSTRUMENT FLYING
V. A. Ponomarenko and A. G. Shishov
Any complication in flight requires a rapid orientation and proper
action on the part of the pilot. The failure to observe these two con-
ditions produces a situation that might lead to an accident. Instrument
flying is an emergency situation the outcome of which depends on the
proper action on the part of the pilot . A study of over 50 cases of
flying and navigation instrument failure shows that proper action is
frequently preceded by erroneous action. There are a number of conditions
that contribute to the pilot ' s errors .
350
Such conditions are produced by the lack of a signal system to in-
dicate the failure of an instrument and permit discovery of such failure
in time. The untimely discovery of the failure, in turn, is due to the
inertness of the instrument which causes a flow of misinformation to the
pilot. These conditions complicate the changeover to a new stereotype
of activity in view of the fact that the failure of the instruments comes
as a surprise to the pilot who is not prepared for it. The major reason
for this entire cause-and-effect chain of pilot 's errors is the misin-
formation, which leads to a dangerous bank and pitching moment, reduced
speed, etc., thereby enhancing the danger of an emergency situation.
A wrong bank indicated by a failing gyro horizon requires the pilot
to remedy this situation immediately, and the result is that he un-
wittingly commits a crude error. A premature descent and a change in
the landing course due to a failing compass are due not so much to the
complexity of instrument flying as to the late discovery of the failure,
to the search for the cause by way of trial and error. If the late
discovery of the failure (due to the lack of a signal system) is conducive
to wrong action, the search for the cause by way of trials connected
with the misinformation merely serves to compound the already committed
error. This is a result of the psychological conflict between the incom-
ing information and the pilot's perception. Speedometer failure during
a night flight in poor weather conditions gave the pilot the wrong in-
formation on increasing speed, and led to his erroneous action. Despite
the fact that the gyro horizon indicated the required pitching moment,
the pilot kept increasing it until the lack of pressure on the control
stick made him realize that the speed was extremely low.
The pilot normally looks at the instrument and perceives the initial
and final position of the arrow; at the same time he perceives kinesthet-
ically the position of the lever. Thus, the movement of the arrow pro-
vides a constant flow of information to the pilot in the form of visual
and kinesthetic impulses.
In this case, the contradictory information between the visual and
kinesthetic perception serves to prolong the search for the reason
behind the increasing speed, thereby jeopardizing the flight. In this
connection, we are right in saying that the lack of a signal warning of
instrument failure not only complicates the work of the pilot but creates
conditions that might be conducive to an accident. The late discovery
of the instrument failure by analyzing the errors already committed
increases the pilot's psychological strain and undermines his confidence
in the outcome of the flight; lack of confidence in the indications of
the other instruments is very dangerous. While increasing his speed
in the clouds in one of the flights, the pilot noted that the speedometer
actually indicated reduced speed. Trying to maintain that speed by in-
creasing the revolutions of the motor, he did not suspect that the
trouble lay in instrument failure, even though, after bringing the plane
351
up to top speed, his instrument still indicated reduced speed. The pilot
usually correlates the indications of the variometer, gyro horizon and
speedometer; in this case, their contradictory information merely served
to confuse him. Instead of changing to instrument flying he made his
first mistake: he began to descend at a great speed. The speed-indicating
arrow continued to drop even though the pilot had already changed his
course into a dive. Receiving the wrong information, the pilot was unable
to determine at first which of the instruments had failed him, as he had
already begun to distrust the indications of the variometer as well as
the tachometer. The distrust in the instruments enhanced the pilot's
psychological tension "... I literally 'ran back and forth' on the in-
strument panel in the painful search for the failing instrument. My
body felt heavy and I experienced the unpleasant sensation of a lack of
self-confidence. When the noise and pressing effort on the control
stick told me that I was moving at a great speed, I realized that the
speedometer had broken down. Constraint and lack of confidence dis-
appeared without a trace".
This lack of confidence in the instruments, caused by lack of a
direct and reliable warning system of instrument failure, is nothing
unusual--it is the result of contradictory information. Thus, we can
see that the contemporary warning system of major instrument failures
does not release the necessary information for immediate perception or
for making a decision based on analysis of that failure. The best sig-
naling system of instrument failure is one that can be clearly per-
ceived by the peripheral vision. Particularly desirable would be an
indicator in the form of a tape with black and white stripes. Instru-
ment failure would initiate the movement of that tape, easily perceived
by the peripheral vision, thus reducing the time it takes to find the
failure .
In conclusion, we should like to point out that the reason for the
errors made in instrument flying, in addition to the misinformation, is
the physical dissimilarity between the major and auxiliary instruments.
It is difficult to imagine a completely satisfactory replacement of the
arrow-type speedometer or variometer by such instruments as a tachometer
or gyro horizon. The indications perceived by the pilot in this case
inform him only indirectly of the current parameters. This fact is due
to the impossibility of arranging two sets of instruments on the instru-
ment panel. In this connection, the use of a sound signal system that
would indicate the required parameters for the auxiliary instruments in
the different stages of the descent, should the main instruments fail,
would greatly reduce the mental strain of the pilot, thereby reducing
the number of his errors.
352
Conclusions
1. The lack of a warning system indicating instrument failure and
the flow of misinformation to the failing instruments are the major cause
of pilot errors in instrument flying.
2. The physical dissimilarity between the major and auxiliary in-
struments is a concomitant condition of erroneous action.
3. The introduction of the proposed failure-warning signals is
one of the methods of improving flight safety.
SOME METHODS OF IMPROVING THE PERCEPTION OF PARAMETERS
CONTROLLED BY A HUMAN OPERATOR
V. A. Popov, A. M. Pikovskiy, Yu. V. Kiselev and Yu. V. Krylov
Modern aviation and space facilities raise a number of new problems
connected with the control of the flying apparatus . Since the proper
functioning of these systems depends to a considerable extent on the
accurate performance by the human operator of individual operations of
the semiautomatic control systems, it is, therefore, urgent to develop
means for improving human perception of the parameters to be controlled.
Recent literature has increasingly stressed the design of such
instruments whose indications are directed not to one but to two and
more human analyzers. Most modern instruments are equipped with a
visual type of indication (an arrow, an electron beam tube, etc.). In
actual practice, however, there are cases when visual indication is dif-
ficult: for example, when the illumination is weak or subjected to great
changes, or when the operator's attention is frequently distracted from
the instrument.
If each particular value of the measured parameter is indicated not
only by a certain position of the arrow on the instrument but also by a
definite frequency or tonality of a sound signal, we will have an in-
strument equipped with a visual and auxiliary sound indication system.
The development of such instruments calls for a familiarity with the
differential audio-frequency thresholds in actual working conditions.
A large number of publications deal with the definition of the
differential audio- frequency threshold, but this information cannot be
used for two reasons: (l) the differential thresholds have been determined
353
by the authors ' external soundproof conditions which do not correspond
to those of the operator's work, (2) the changing audio frequency in
the mentioned investigations was of a discrete nature. But in the sound
indicator in which we are interested the tonal frequency should be
changing continuously as the parameter to be controlled is, as a rule,
undergoing continuous change.
In our investigations, the planned changes in the frequency sepa-
ration were made by means of the sound generator 3G-2A at a speed of
3-5 hertz per second and at frequencies of 685-1,800 and 3, ^00 hertz.
The external auditory interference level amounted to 75~80 decibels.
A total of 256 experiments were made, revealing that the differential
audio-frequency threshold, by the mentioned terms of the definition,
amounts to 0.02 of the frequency under consideration. This is the
figure that should be used to calculate the sound indicator.
There is no doubt that if the information on the changing parameter
under control flows through a visual as well as a sound channel, when
observation of the visual indicator is difficult, the perception of the
mentioned parameter can be improved. But can the perception of a param-
eter be improved by an additional sound indication if the operator ' s
attention is concentrated on the visual indicator? Solution of that
problem required the investigation of certain aspects of the interaction
between the auditory and visual analyzers. This was done with a test jig
consisting of a 3G-2A audio -frequency generator which was connected to
an ICH-6 frequency meter in such a way that every position of the fre-
quency meter arrow corresponded to a certain value of the sonic frequency
in the generator. The sound in the generator was changed by a smooth
and even turn of the generator detuning knob by an electric motor. The
changing sound was recorded on a circular calibrating generator scale
where a shift of the control handle by one scale division corresponded
to a frequency change of one hertz .
The experiment was made by three methods. The first method, in
which information on the changing parameter was fed only to a sound
channel, was similar to the one used to define the differential frequency
thresholds (altitude). With 6 to 8 signals for each of the frequencies
under consideration- -685, 1,800 and 3,^00 hertz --the information on the
changing parameter was fed only through the visual channel. The test
object was then asked to pay close attention to the position of the arrow
on the frequency meter indicator. A turn of the detuning knob of the
audio-frequency generator changed the position of the arrow on the fre-
quency meter. The sensitivity of the frequency meter arrow at 685,
1,800, and 3,1+00 hertz frequencies was 0.00*4-5 degree/hertz, 0.0018 de-
gree/hertz and 0.0009 degree/hertz, respectively. Noting the deflection
of the arrow, the test object pressed a button which brought the arrow
to a stop.
35^
By the last method, the information on the changing parameter was
fed simultaneously through a visual and sound channel. A button was to
be pressed as soon as the change in the parameter was discovered on
either of the two channels. In all the methods, the deflections were
recorded by the number of divisions on the detuning scale of the audio-
frequency generator. The frequencies under consideration as well as
the alternation of the auditory and visual indications were constantly
changed in order to exclude the operator's training effect. A total of
756 tests were made and each experiment was repeated 6-8 times.
All experimental results were statistically processed, the data for
each test subject were averaged up, and the percentage ratio of the
minimum parameter deviations noted by the test subject (based on sepa-
rate visual or auditory information) to the minimum parameter deviation,
as reported simultaneously through two channels, were calculated. An
indication of over 100 percent meant that the parameter perception based
on simultaneous information coming from the visual and auditory channels
was improving, and if less than 100 percent it meant deterioration.
The average ratio, reflecting the interaction of the analyzers in
the test subjects, was 110 percent at 685 hertz, 111. 9 percent at 1,800
hertz, and 106.2 percent at 3,^00 hertz. The same ratio for a general
overall 95 percent probability lies within the following ranges : at 685
hertz, 110.0 + h.3 percent; at 1,800 hertz 111.2 + 5.5 percent and at
3,000 hertz 106.2 + k.l percent. Thus if the information on the chang-
ing parameter is fed through the visual and auditory channels at a time
when the test subject's attention is concentrated on the visual indica-
tor the improvement in the parameter perception accuracy amounts to
about 6-11 percent .
Individual test subjects find it considerably earier to perceive
the parameter under control if the appropriate information is fed simul-
taneously through the visual and auditory channels. In this case, the
above-mentioned ratio amounts to 135-155 percent. But the problem in-
volving the stability of this effect in individual test subjects is sub-
ject to a further study. In particular, it would be practical to make
such an experiment in a dynamic trainer in which the nature of the op-
erator's activity is most similar to his actual conditions of work.
Conclusions
1. A combination of visual and auditory indication improves the
perception of one parameter as compared to either visual or auditory
indication by 6-11 percent. In certain test subjects such an improve-
ment amounts to 35-55 percent.
355
2. The calculation of the sound signal for instruments with a dual
indication system should be based on the fact that the differential
audio -frequency threshold is not less than 0.02 of the frequency under
investigation .
3. Semiautomatic control systems whereby the parameter is subject
to the most accurate determination on the part of the operator should be
equipped with a dual indication system (visual and sound). It is de-
sirable to select the type of operators who reveal a higher capacity for
determining the changes of any parameter in conditions of analyzer
interaction.
THE REACTION OF THE ORGANISM TO THE INFORMATIONAL
CHARACTERISTIC OF A STIMULUS
V. A. Popov and A. S. Khachatur 'yants
One aspect of research in aviation medicine deals with the proc-
esses of airplane piloting. Considerable success in this field has
been achieved by the development and utilization of complex devices
designed to record the various aspects of pilot activity and condition
in flight (K. K. Platonov, V. A. Popov, A. M. Pikovskiy, Ye. R. Derev-
yanko, etc.). But despite their value, these efforts were primarily
descriptive in nature. The development of cybernetics and the theory
of information made it possible not only to attempt a quantitative de-
scription of the elements involved in the piloting process but also to
determine the new aspects of their analysis.
The dependence of the characteristics and speed of a human reaction
on the varying probability of a signal appearance has been investigated
in a number of publications (by R. M. Zarakovskiy, M. A. Alekseyev, etc.)
These efforts were limited to a study of the elements characteristic of
the time the test subject is introduced into a probability medium. Of
undoubted interest also are the characteristic reactions to the signals
of such a system whose probability characteristics have already been
learned by the test subject. The methods developed have enabled us to
record these characteristics fairly accurately; they may be looked upon
as a laboratory model of elementary activity based on a purposeful pre-
selected probability characteristic of the surrounding events.
The experiments were designed to study the changes in the test
subject's reactions to a surrounding medium characterized by various
probabilities under the effect of various specific factors . It would be
356
expedient, first, to trace the changes as the (informational) character-
istic of each of the signals forming the model of the external medium
fades from the memory of possibilities. In the experiments, the infor-
mational complex to be assimilated by the test subject consisted of 5
sound signals occurring at such a frequency that their informational
characteristics corresponded to 0-5, 1-78, 3> and ^ "beats. A repeat of
these test programs every hour revealed a peculiar picture of the infor-
mational value of certain individual signals fading from the memory of
the test subject. Cited in Table 1 are the generalized results of the
tests with 10 subjects.
Table 1
Informational characteristics
of signal
(in beats)
Effective duration
( in hours)
0.5
1.78
3
k
5
6.5
29
55
It may be seen from the table that there is a definite rela-
tionship between the duration of the informational significance of the
signals in the memory and the magnitude of that significance. Attention
is called to the fact that this relationship is logarithmic rather than
linear in nature .
The changes in the hidden time of the reaction to each signal
of the mentioned complex amounted to a progressive reduction of that
time. In the graphs containing an outline of function t = f (H), the
test result curves for each hour changed their slope and approached the
X-axis. The comparison of the submitted and following information was
made easier by calculating the derivative function t = f (h), that is by
determining the magnitude — referred to by us as the tension factor.
dH
In the cited experiment, that factor took on the following values: 0.06
sec/beat one hour later, 0.0U sec/beat two hours later, and 0.02 sec/
beat five hours later.
In the following series of tests, immediately after assimilating
the informational structure of the color- signal complex, the test sub-
ject was subjected to a prolonged effect of acoustical noise with an
intensity up to 1014- decibels. By the end of the third hour, the function
t = f (H) was seen to be disrupted; if the noise effect was continued
357
after that, the restoration of the function began 20-25 minutes later.
The quantitative characteristic of these changes can he traced by com-
paring the tension factors (Table 2).
Table 2. The Changing Tension Factor Under the Effect
of Noise
Time of change
Tension factor
After the introduction into the
0.14
0.09
0.04
After three hours of noise. . . .
function disrupted
0.08
An entirely different type of changing tension-factor was produced
when the test subject was under the effect of alcohol. The introduction
of alcohol (0.5 -0.75 ethyl alcohol per 1 kg of weight; per os) made the
reactions more sensitive and increased the tension factor. Two hours
later, the observable normal effect of this informational structure was
almost completely demolished, and the tension factor could not be de-
termined. Six hours later, the functional relationship was restored,
and then died away at a smooth but somewhat faster than usual rate.
The development of these events is outlined in Table 3.
Table 3
No.
Data reading time
Tension factor
in sec/beats
1
2
3
k
5
6
7
8
9
10
0.16
0.29
0-33
function disrupted
function disrupted
0.05
function disrupted
0.16
0.09
0.02
Li
358
A similar system was also used for the study of other deleterious
factors, such as oxygen deficiency, barometric pressure drops, a pro-
longed unchangeable position, etc. A comparative analysis of these data
showed that the shorter retention period of the informational signifi-
cance of the signals in the human memory was a common feature of all the
tests. The nature of this type of memory loss is largely specific to
the effect of individual factors.
Conclusions
1. The demolition of the probability characteristics of the signals
mastered by man is accelerated under the effect of deleterious factors
on the organism.
2. The characteristic reactions of the human being to a variety
of stimulus probabilities may serve as a criterion for estimating his
capacity for work under the effect of various factors on the organism.
ELECTROCARDIOGRAMS IN DOGS DURING EXPOSURE TO CERTAIN
ALTITUDE FACTORS
V. L. Popkov and I. N. Chernyakov
The normal EKG of dogs has several specific features : the aver-
age pulse in dogs is twice as fast as in man; respiratory sinus arrhyth-
mia is more sharply pronounced; inversion and polymorphism of the T wave
with displacement of the ST interval above and below the isoelectric
line is not a pathological sign; and the Q and S waves are not constant
and are sometimes missing under normal conditions (Sapov (1955),
Gurevich, Kvitnitskiy (1956), Homazyuk and others (i960), Petersen and
others (1951), Grollman and others (1952), Fabre and others (1955),
Bober (1956), and other writers). These characteristics of dog EKGs
have been taken into consideration in our analysis of the experimental
material. The experiments were conducted on 11 dogs.
A total of 373 EKGs (with the three standard leads (I, II, and III))
were taken on 11 dogs. The animals--immobilized in a prone position
while EKGs were being taken--were subjected to hypoxic hypoxia (in a
pressure chamber atmosphere with an oxygen deficiency equivalent to an
altitude of 9 km), to the effect of respiration of high-pressure sea
level and high-altitude atmospheres, and to the effect of a pressure
reduction of 0.3 abs atm.
359
Under normal conditions, the EKG P wave in all experimental dogs
was positive for the three standard leads . Only one EKG showed an iso-
electric P , and in another case a weakly negative PP fluctuated be-
tween 0.05 and 0.2 mv in the initial tests (instead of between the more
frequent limits of 0.1 to 0.15 mv) . The largest of all the waves, the
P-Pp, varied from 0.05 to 0.^5 mv, with an average value of 0.25 mv.
The P normally varied within the extreme limits of +0.3 mv to -0.1 mv,
with an average value of +0.1 mv. During hypoxic hypoxia (pressure
chamber oxygen deficiency equivalent to an altitude of 9 km) a drop in
the P , P , and especially the P waves, was noted. The lower limit
values of P-., P p , and P were consistent with normal P wave variations.
The variations of P , P , and P during respiration of high-pressure
sea level atmospheres did not exceed the normal limits . After reduction
of ambient pressure by 0.3 abs atm, and during respiration of high-
pressure high-altitude atmospheres, P , P , and P increased but did not
exceed the upper limits of normal P wave variation. The P wave increase
was dependent on the amount of excess pressure.
The limits of EKG R wave variation in the initial tests were 0.4 to
1.8 mv for R ± , 1.0 to 1.8 mv for R , and O.55 to 0.8 mv for R . The
effect of acute hypoxia (oxygen deficiency equivalent to an altitude of
9000 m) produced a regular decrease in R values for all three standard
leads (a decrease of 0.1 to 0.3 mv in R , 0.05 to 0.5 mv in R ? , and 0.05
to 0.3 mv in R.,). During respiration at high-pressure, sea-level atmos-
pheres, R usually remained constant or else increased by 0.05 to 0.3 mv.
R-^ and R were characterized by opposite-tending changes: in the majority
of experiments, R decreased by 0.1 to 0.2 mv while R increased by 0.05
to 0.3 mv. It is interesting to note that R variations changed in the
same manner after the 0.3 abs atm pressure drop and during respiration
of high-pressure, high-altitude atmospheres: R, decreased by 0.1 to 0.3
mv, R Q remained constant or increased by 0.05-0.1+ mv, and R increased
d 3
by 0.05 to 0.3 mv. No direct ratio between R values and the pressure
increase of the respired atmosphere was noted. The R wave variation under
360
the above-mentioned conditions did not exceed the normal limits of R
fluctuation. The observed tendencies of R change with increased pres-
sure are probably due to the altered position of the heart in the chest
cavity under these conditions.
It was noted that of all the EKG waves observed in dogs, the Q and
S waves were the least stable even under normal conditions, disappearing
and reappearing on successive recordings of the same dogs made at various
times. In the initial tests, the Q, and Q values varied from 0.0 to
0.3 mvj in approximately 50 percent of the normal EKGs, Q, and Q were
not observed at all; Q was nearly always absent under normal condi-
tions. Hypoxia, reduced pressure, and respiration at high-pressure,
sea-level, and high-altitude atmospheres caused new Q, and Q waves to
appear and a Q wave to be formed in the EKG. During respiration at
high-pressure, high-altitude atmospheres, all three waves (Q-,, Q , and
Q ) were observed in the majority of the EKGs . The value of Q usually
did not exceed 0.2 mv; i.e., it remained within the limits of normal
variation.
Under normal conditions, the S wave was absent from the dog EKG.
S 2 and S varied from to 0.7 mv (Sp) and from to 0.9 mv (S ). Dur-
ing hypoxia and following the pressure drop of 0.3 abs atm, Sp and S
usually decreased. During respiration at high-pressure, high-altitude
atmospheres, an S wave appeared in the EKGs, but its value did not
exceed 0.05 to 0.1 mv. Variations of S ? and S in high-altitude tests
remained steady within the limits of 0.05 "to 0.15 mv.
The T wave in the dog EKG was characterized by a great diversity
of configuration and even under normal conditions might be isoelectric,
negative, or even two-phased (both positive and negative phases) on
successive recordings made on the same dog at different times. As a
rule, T, was negative under normal conditions; T was the most variable
and might equally well be positive or negative; T was positive in the
majority of cases. In individual instances, during the initial tests,
361
T and T were two-phased. ST and especially ST frequently dropped
23 2 3
"below the isoelectric line on the normal EKGs, which is not a pathological
sign in the dog EKG. Under the effect of hypoxic hypoxia (pressure
chamber atmospheres), negative T and T waves showed an increased shift
in the negative direction, and positive T 2 and T values dropped; during
hypoxia, the two-phased T was the most frequently observed. The de-
livery of excess pressure in G Sh and VKK sea-level atmospheres, the
O.3 abs atm drop simulating high altitudes, and respiration at high-
pressure, high -altitude atmospheres all produced a shift of T^ T,,,
and T in the electropositive direction (values of negative T-^ T ,
and T decreased and positive T , T , and T values increased).
Under normal conditions, the PQ interval was extremely stable,
varying from 0.09 to 0.12 sec in different individual dogs (in most cases
0.10 sec). Following reduction in pressure, and during respiration of
high-pressure sea-level and high-altitude atmospheres, the PQ interval
tended to decrease to 0.09 to 0.08 sec.
The QRS interval was one of the most stable values in dog EKGs,
both under normal conditions and during physiological effects. In the
initial tests the QRS was always from 0.05 to 0.06 sec. During respi-
ration at high-pressure, high -altitude atmospheres, the QRS was equal
to 0.05 sec.
The QT interval is normally from 0.19 to 0.20 sec. During exposure
of the organism to external factors (hypoxia, reduced pressure), QT
varied from 0.17 to 0.21 sec. On some of the EKGs recorded during respi-
ration of high-pressure, high-altitude atmospheres, QT decreased to 0.16
sec.
The RR interval was the most labile interval in the dog EKG, vary-
ing from 0.3^ to 0.60 sec under normal conditions. The systolic index
(based on the smallest RR interval in the EKG) normally fluctuated from
35 percent to 60 percent (average 14.5 percent); this is associated with
the very marked instability of pulse typical of dogs (respiratory sinus
arrhythmia). During exposure to hypoxia, the systolic index usually in-
creased to 53 percent to 6h percent. During respiration at high-altitude
atmospheres at high pressures, the systolic index varied from kO percent
to 63 percent (an increase of 8 to 31 percent over initial test values).
The experimental material given above permits us to draw the following
conclusions :
362
1. The method of dog EKGs combined with other study methods per-
mits evaluation of the nature and direction of physiological changes
accompanying exposure of the organism to certain factors of high-
altitude flight (hypoxia, reduced ambient pressure, and respiration of
excess pressure atmospheres).
2. The consistent nature of EKG changes in dogs after reduction
in ambient pressure, as well as the differences between the EKGs of
dogs exposed to excess pressure and those of dogs exposed to hypoxia,
indicates that the factors determining these EKG changes are the de-
livery of excess pressure in VKK and G Sh barochambers and the result-
ant alteration in the position of the heart within the chest cavity.
3. Study of the characteristics of EKGs in dogs permits us to
conclude that the changes in dog EKGs accompanying the respiration of
excess pressure atmospheres are the result of physiological adaptation
of the organism to its environment and do not exceed the limits of
normal EKG variations in dogs .
EFFECT OF OXYGEN STARVATION ON MOTION SICKNESS
N. A. Razsolov
The investigation of rocking accompanied by moderate hypoxia is of
great importance in aviation practice. However, up to the present,
only a few works have dealt with this problem (V. I. Boyachck, K. L.
Khilov, I. la. Borshchevskiy, A. P. Popov, B. V. Tolokonnikov and
others), and these have by no means covered all aspects. Consequently,
there is obvious need for more elaborate study of this problem.
Our research on the effect of oxygen starvation on motion sickness
utilized 3 men and 2 women, 25- 35 years old, who. following determination
of physical fitness, were subjected to cumulative studies of the vesti-
bular apparatus after G. G. Kulikovskii in double experiments with rota-
tion (OF.) in three planes, rocking on four-pole (or four-valve) swing
during 15 minutes and once again in double experiment with rotation
(OP ). Four subjects showed relatively high statokinetic stability:
one showed zero degree of 0P o , two showed first degree of 0P o . one
showed a vegetative reaction of second degree of OPp. Only one subject
363
(female) experienced vomiting during the 7 minutes of rocking on the
swing- -second degree (Kp).
Rocking was instituted by the double rotation method (N. N. Lozanov,
I938) in a Barany armchair with a speed of 1 rotation per 2 seconds.
During 30 rotations, the subject bent bis head and torso forward 15 times
to the horizontal plane and straightened up an equal number of times.
Rotation was always toward the right, clockwise. During rotation, the
eyes were closed; no bandages or screens were used. There were 5 rota-
tion tours, at intervals of k minutes. The start of the illusion of
"rocking" was recorded during rotation, and, following each tour, these
reactions were tested: pulse frequency, arterial pressure by the oscil-
lographic method, the duration of the illusion of counterrotation,
hyperemia or pallor of the face, hyperhydrosis, nausea and vomiting and
other symptoms of motion sickness . After this, the subject was re-
quested to perform measured dynamometrics by compressing a hand dyna-
mometer in his right hand with an effort equal to one-half maximum
manual dynamometrics and then performing a correction text for 2 min-
utes. Subjects in the initial trial tests (not taken into consideration)
performed correction tests of 2 minutes, 20- 30 times, always crossing
out the letters "K" and "R" on same type correction blanks; consequently,
in the tests under consideration, they attained high-quality, highly
stable productivity. On 3 people, initial average productivity for 2
minutes amounted to 1600, II87 and 1208 marks, and in 2 it was 8^0 and
805 marks (or signals).
The present work covered three types of control investigations. In
the first, the subjects were in the pressure chamber, but not subjected
to oxygen starvation (shortage) or rocking. These subjects, for whom
pulse frequency and arterial pressure were registered, performed regu-
larly measured dynamometrics and correction tests. In the second, the
subjects were subjected to rocking in the pressure chamber, but without
lifting (elevation). In the third, the subjects were elevated to a
height of UOOO ra. Subjects in the principal test were subjected to rock-
ing at a lj-000 m altitude. There was a total of 53 tests: each subject
performed 2-3 introductory get-acquainted tests, 6 control tests each and
2 principal tests each. To eliminate training, the tests were done on
every 5th day (with an interval of 14- days). At the completion of test-
ing, which lasted 2 months, all subjects showed approximately the same
degree of vegetative reactions .
Results of Investigation
In spite of the fact that our method of rocking differed from that
of N. N. Lozanov in number of rotations and that we used a different
method for registering arterial pressure, we still found it possible and
convenient to evaluate the degree of vegetative reactions by the scale of
statokinetic stability as determined by the cardiovascular reflex (Lo-
zanov and Baichenko, 1938).
36^
In k subjects, changes in pulse frequency, as well as maximum and
minimum arterial pressure in all tours of rocking on the ground (averag-
ing from the figures from two tests), were expressed, in the majority of
cases, by 5-4-5 points (or marks), and only twice dropped to 3.5 and
3.75 points, at which time the subjects felt nauseated. One female sub-
ject had vomiting during the third tour of on-the-ground rocking, her
statokinetic stability decreasing to 3-0 points (marks); after k minutes
her general condition improved and she was able to continue rocking, and
in tours IV and V her score rose to k.O and k. 25 points. During the
rocking at the kOOO m altitude, the statokinetic stability, as evaluated
by the cardiovascular reflex, dropped to 0.5-0.25 points in k stable in-
dividuals in the majority of tours. One female subject, after the third
tour, experienced vomiting, with a stability rating of 3.25 points; after
a 4-minute rest period, vomiting ceased, but, after tour V of rocking,
vomiting resumed, with stability at 3.5 points. Average arterial pres-
sure during rocking and in a state of oxygen starvation changed very
insignificantly .
During the first tours of rocking, all subjects noted the illusion
of "rocking, " which started with the 10-20th rotation and continued to
the end of rotation. In subsequent tours of rocking, "rolling" appeared
with the lU-25th rotations; in some statokinetically stable individuals
it did not appear at all. In most cases, the illusion had the nature of
"rolling motion," with subjects being "thrown" from side to side. After
the rocking stopped, all subjects in the first tours experienced an
illusion of counterrotation, lasting from 3 to 25 seconds. In subsequent
tours of rocking, the duration of this illusion was reduced to 2-10
seconds.
During rocking under conditions of hypoxia, no essential changes
were observed in the nature and duration of the illusions of "rolling"
and counterrotation, as compared to the rocking under usual conditions .
After completing 50 tours of rocking under usual conditions, hyper-
emia of the face was reported 12 times; pallor of the face, 15 times;
hyperhydrosis, 20 times; feeling of warmth, 8 times; nausea, 13 times;
vomiting, twice; fatigue and headache, 5 times. When rocking under the
conditions of hypoxia, hyperemia of the face was observed 16 times;
pallor of the face, ll+ times; hyperhydrosis, 7 times; nausea, I3 times;
vomiting, twice; euphoria, 5 times; fatigue and headache, 8 times.
In the first control examination, averaging 2 minutes for each of
50 control tests, 1127 marks, or points were reviewed. Permissible
errors here were taken to be 0.24 marks (points). During rocking under
usual conditions, average productivity was lowered to 1071 points (95
percent of the initial level), the number of errors went up to O.36
points (150 percent of the initial level). At the 1*000 m altitude pro-
ductivity of the control test went up to H67 points on the average
365
(103^5 percent of the initial level), and the number of errors went up
to 0.1*6 points (191 percent of the initial level). When rocking under
conditions of hypoxia, productivity was 11^8 points (101.8 percent of the
initial level), and the number of errors went up to 0.5^ points (225 per-
cent of the initial level).
Under the usual conditions, the average error in the rationed hand
dynamometry in 50 measurements, not taking into account the points of
errors over (+) or under (-) the given figure, was l.l8 kg. Here, the
sum of errors with the plus sign was U0 kg, and the sum total of the
points of errors with the minus sign was 19 kg, the ratio being 2.1:1.0.
During the time of rocking under the usual conditions, the average
error was equal to 2.l8 kg (187.7 percent of the initial starting level).
The sum total of errors with the plus sign was equal to 99 kg, that with
the minus sign, 10 kg, the ratio being 9.9:1.0. Under conditions of
oxygen starvation, the average error proved to be O.96 kg (81.3 percent
of the initial starting level). The sum of errors with the plus sign
was 36 kg, those with the minus sign, 12 kg, the ratio being 3:1. Dur-
ing rocking under conditions of oxygen starvation the average error of
the rationed dynamometry was 2.^2 kg (205 percent of the normal). The
sum total of the errors with the plus sign was 100 kg, those with the
minus sign, 11 kg, for a ratio of 9:1.
Conclusions
1. Rocking after the method of twofold rotation makes it possible
to elicit a latent form of rocking in statokinetically stable people
and a marked form of rocking in less stable persons.
2. During rocking under conditions of oxygen starvation, vegetative
reactions are intensified.
3. During both latent and marked forms of rocking, higher nervous
activities are disrupted, apparently, at the expense of weakened inner
cortex inhibition, causing a poorer quality performance of correction
test and rationed manual dynamometry.
k. Oxygen starvation at the U000 m height apparently results in
weakening the inner inhibition, which is reflected in poorer performance
of the correction tests.
5. During rocking under conditions of oxygen starvation, a still
greater cumulative disturbance of higher nervous activity is observed.
366
THE IMPORTANCE OF THE STUDY OF TYPES OF HIGHER NERVOUS ACTIVITY
IN MAN IN SELECTING AND TRAINING FLIGHT PERSONNEL
A. A. Rogov, T. T. Gorlanova, M. M. Kantorovich and N. T. Kovaleva
The very rapid development of aviation technology, both in the
field of air transport, and in the utilization of cosmic space, im-
poses greater and greater demands on the pilot's organism as a whole
and his nervous system in particular. Up to the present time, insuf-
ficient attention has been devoted to the study of the higher nervous
activity of man, although this problem is of great importance in flight
and cosmic medicine.
Underestimation of the type- specific characteristics of higher
nervous activity may be one of the causes for the diminution of effi-
ciency during flight, especially under complex or difficult conditions.
Consequently, contemporary study of type- specific nervous system char-
acteristics is of great importance in selection and training of flight
personnel and particularly of astronauts .
Even in I. P. Pavlov's lifetime, his school had maximum recourse,
in classifying types of human nervous system, to clinical histories with
exhaustive anamesis records (B. N. Birman, S. N. Davividenkov, L. B.
Gakkel ' and others). L. B. Gakkel', Z. I. Biryukova and F. P. Mayorov
and others have prepared special questionnaires to evaluate characteris-
tics of higher nervous activity in humans . It should be noted that
medical history data should be supplemented with material from observa-
tions of the behavior and disposition.
For objective study of specific traits of the nervous system of nor-
mal man, we used the method of vascular reflexes, combined with the medi-
cal history and observation of behavior.
Selection of the vascular reaction, as an index of nervous proc-
esses in the cerebral cortex, was not accidental. In their works, K. M.
Bykov, A. A. Rogov, A. T. Pshonik, and others have established a close
interrelation between the higher CNS spheres of the vascular system.
Many authors (Rogov, Pshonik, Suvorov, Derkach, Kovaleva, Gorlanova,
and others) have shown that the cortical processes exert an influence
on the nature of the plethysmographic curve.
We observed a group of healthy individuals, most of whom worked
and lived under identical conditions, and recorded their vascular re-
actions plethysmographically by A. A. Rogov 's technique. Background
plethysmograms, which were studied under nonconditioned and conditioned
vascular reflexes, furnished--by their configuration changes and un-
dulating variations- -preliminary data for evaluating the chief character-
istics of the nervous system. Thus, for well-balanced individuals, the
367
background plethysmograms beginning with the very first test have a
smooth curve appearance. If at any moment there is any undulation, it
soon disappears completely.
Background plethysmograms of persons with a severely unbalanced
type of nervous system, as a rule, are undulating, and may retain a
wavy ripple effect during the time of stimulation.
In weaker types, with balanced traits, background plethysmograms
appear as smooth curves; while in persons with unbalanced traits, ple-
thysmograms, as a rule, show constant undulation.
In view of the great variety of vascular reactions in people of
different types of higher nervous activity, evaluation from background
plethysmograms alone is insufficient. Thorough understanding requires
taking into account vascular reactions in response to the effect of
both nonconditioned and conditioned stimulations.
Vascular reactions to nonconditioned stimuli vary in degree of
marking. Variations (or differences) in vascular reactions, as shown by
our data, depend upon the type-specific characteristics of higher ner-
vous activity in man.
In individuals with well-balanced nervous systems nonconditioned
vascular reflexes are pronounced and characterized by a considerable
drop in plethysmogram, i.e., marked compression of the blood vessels.
In individuals with severely unbalanced nervous systems, they are quite
pronounced, inconstant, and appear against the background of an un-
dulating curve. In individuals with weak nervous systems, as a rule,
they are either poorly expressed or absent, and of an inert nature. In
individuals of weak type, with traits of equilibrium, they appear against
the background of a smooth curve; in the same persons with traits of im-
balance, they appear against the background of undulating plethysmogram.
The following discussion utilizes Pavlov's nervous system types,
which he based on his doctrine of conditioned reflexes .
Conditioned vascular reflexes in individuals with well-balanced
mobile nervous systems (sanguine) are distinguished by rapid formation
and quick stability, with little change in magnitude after formation.
As a rule, they appear against the background of smooth plethysmograms.
Differentiated inhibition is developed comparatively rapidly with 7-8
applications of negative inhibition and they become stable after lj-2
applications of stimulants without reinforcement.
In individuals with well-balanced inert nervous systems (phleg-
matic), vascular conditioned reflexes do not particularly differ from
those of people with well-balanced mobile nervous systems, although
368
vascular reactions to stimulation take place more slowly and show a
slower return to their initial starting level.
In persons with greatly unbalanced nervous systems (choleric), as
distinguished from those with well-balanced processes, the positive and
negative vascular conditioned reflexes are subject to considerable
fluctuations, frequently appearing against the background of an un-
dulating curve .
In individuals with nervous systems, (melancholic) with traits of
equilibrium, vascular conditioned reflexes develop with great difficulty,
are unstable and primitive in scope, and sometimes may even be para-
doxical. Differentiated inhibition is frequently formed more quickly
than in individuals of other nervous system types. In individuals of
the weak type, with traits of imbalance, these reactions occur against
the background of an undulating curve.
It should be noted that evaluation of nervous system types should be
based not on one single trait but on the sum total of all indexes.
In this manner, the nature of vascular reflexes in combination with
medical history and observations of behavior may serve as objective
criteria in selecting candidates for flight service. It may be assumed
that the ideal is the well-balanced mobile type of nervous system and in
our opinion, astronauts should be of this type.
The study of the specific characteristics of nervous system types
in normal man may offer additional insights in selecting and training
specialists in aviation and cosmonavigation.
SOME REGULAR PATTERNS IN THE EFFECT OF ACCELERATION
ON THE ORGANISM
D. Ye. Rozenblyum
1. This article presents some of the author's theoretical concep-
tions on the physiological effects of acceleration on the organism.
2. Deviations from normal gravitation, in the direction of im-
ponderability or of increased gravitation, conditioned by the effect of
radial accelerations, introduce life activity changes of varying nature
and scope, depending upon the index of change in gravitation field, the
position of the animal in the evolutional scale, and individual charac-
teristics.
369
3. In physiological reactions to mechanical stimuli, involving
accelerations of different physical nature, we may determine some gen-
eral, even though not identical, traits, and contingent essential dif-
ferences .
k. In the effects of radial accelerations, depending upon their
physical parameters and the functional state of the organism, we may
distinguish two "basic phases: (l) the phase of relative compensation,
and (2) the decompensation phase.
5. In the phase of relative compensation some functions, mostly
the vital ones, are intensified, and others are temporarily inhibited
by way of compensation; the mechanical forces exceed the thresholds
of individual stability. This phase is neither perfect, nor stable;
multiple factors, which inhibit the defense neurohumoral mechanisms,
easily destroy the attained adaptation. It is important in demon-
strating the physiological mechanisms of adaptation to radial accelera-
tions .
Since the field of centripetal acceleration is equivalent to the
acceleration of earth gravitation, one is justified in concluding that
the physiological systems of adaptation to earth gravitation carry the
load of the fight against increased gravitation.
The author discusses at some length the role of the defense tonic
muscle reflexes, in this situation, with various starting mechanisms;
the role of the mechanisms of regulating blood circulation in particu-
larly important vital organs; the mechanism of compensation of ventila-
tion insufficiency, should it arise; and the role of vestibular appara-
tus.
6. Study of the decompensation phase permits delineation, in the
chain of mutually connected phenomena, of some leading links, which
normally limit transference of accelerations.
7. Data are reported on the physiological analysis of high sta-
bility (resistance perhaps) of insects during acceleration; this is of
interest in the theory of effect of acceleration on biological objects.
8. Possible remote chronic effect of radial accelerations are
discussed.
370
THE NERVOUS SYSTEM'S ROLE IN THE ORGANISM'S REACTIONS
TO ACCELERATIONS
B. M. Savin
The gravitational field is one of the few constants in the environ-
ment, and even though gravitation appears, at first glance, of little
significance, it is precisely that which played the determining evolu-
tionary role in the development of a number of functions and formation
of new structures.
Although man is often obliged to face changes in the intensity of
gravitation, in most cases, the range of variations (natural or artifi-
cial) seldom exceeds + 0.5 gram. However, flying conditions encountered
on high-speed planes are quite different from those met in cosmic air-
craft. From the moment of takeoff to landing, the crew of a cosmic
airship is constantly under gravitational conditions different from
those on earth. The cause of this is not so much the lessening of natu-
ral gravitation, associated with the departure of the cosmic airship
from the earth's surface, but rather the effect of outside forces, im-
parting acceleration to the cosmic airship and the astronauts within it.
Depending upon the magnitude of the forces in operation and their direc-
tion with reference to the vector of the gravitation field on earth,
two dissimilar states may arise during transmission of acceleration:
"overloading" (excess load or surcharge) and partial or complete dynamic
incompatibility. From the purely mechanical point of view, both states
represent various degrees of mechanical tension of the body structures
(deformation) .
In overloading, the deformation is more marked than under usual con-
ditions on the surface of the earth when the body merely undergoes the
effect of the earth's attraction. Under dynamic incompatibility (par-
tial or complete), mechanical tensions in the body structures are either
sharply diminished or completely absent. In this manner, the state of
dynamic incompatibility represents a particular case of overloading, in
which the excess is near zero value.
Some of the most prominent manifestations of the changes in physio-
logical functioning of the organism under artificial increase in gravi-
tation (overload) are disturbances of hemodynamics. Scientific works
have manifested, until rather recently a perfectly unjustified tendency
to limit mention of this problem. This was reflected in the attempt
on the part of the research workers to disclose only such regular pat-
terns (laws) of the changed hemodynamics which are conditioned by purely
mechanical causes (hydrostatic factors). Actually, in cardiovascular
functional changes during overload, an exclusively important role belongs
to the neural reflex reactions . Depending upon the amount of overload
and its direction with reference to the axis of the body, the duration
371
and repetition of the effect of the reflex reaction on the organism may
exhibit considerable variations. In one case, they may be favorable for
the equilibrium of the organism under the changed mechanical conditions
of its environment, and in such case the reactions should be considered
totally as compensatory; in other cases, the appearance of these reflex
reactions facilitates the appearance of even more marked disturbances
in the state of hemodynamics. These differences in the reflex mechanisms
of circulatory regulation are based on shifts in CNS functional state
and, primarily, in the condition of the vasculomotor center and the
vagus nerve centers .
An analysis of the changes in cardiovascular function during over-
load permits delineation of a number of different phases or periods,
each reflecting the shifts (displacements) in the functional state and
in the centers which regulate the cardiovascular system. The sequence
of these periods is as follows: compensatory reaction (latent), high
compensation, development of decompensation, restoration of compensa-
tion, return of the cardiovascular regulating mechanisms to initial
state. The first four periods, from the standpoint of time, belong to
the moment of reciprocal intereffect of the organism and the changed
conditions of gravitation; the last two, to the aftereffect.
When the organism experiences functionally permissible overbad-
ings, then only such states which take place in the form of the first
three periods are typical for the cardiovascular centers. When the
overload effect becomes too strong for the organism, the second and
third periods are obliterated and almost immediately there occur some
pathological reflexes which result in decompensation phenomena.
Research has established that with functionally permissible over-
loads the leading role in cardiovascular functional changes belongs to
the appearance of an unusually powerful combination of stimulations.
The principal role then belongs to those stimulations which come from
the side of the baroreceptors of the vascular system, in particular the
receptors of the veins. Under overloads which approach the limits of
tolerance, disturbances of the cerebral circulation begin to assume
great importance and new interrelationships create a peculiar, vicious
circle. In the functional state of the vascular motor center, phase
states, typically, appear, characterized by paradoxical reactions, in
particular, a depression reaction to the elimination of the inhibitory
influences from the side of baroreceptors of the sinocarotid zone.
Functional disturbances of the reflex mechanisms that regulate the
cardiovascular system are reflected in the organism's decreased capacity
for adaptation and other phenomena which are alleviated only by sec-
tioning of the vagus nerve .
In the systematic effect of overloads, the organism's capacity to
balance the changed conditions of gravitation increases sharply. In
372
planning training for the effect of overloads, the leading role belongs
to the higher CNS branches.
ELECTROENCEPHALOGRAPHS EXAMINATION OF FLIGHT PERSONNEL
DURING LONG FLIGHTS
L. V. Sadovnikova
To examine personnel who fly gas-turbine planes--in 8-9 hour flights-
ve used, along with other physiological methods, the method of electro-
encephalography (EEG), which has recently been used successfully to solve
problems of physiology of labor.
Flying is one example of complex work entailing physical, nervous,
and psychic tension. Of practical interest here is the use of EEG to
evaluate the mobility of CNS processes.
Data on the effect of flight on the pilot's brain biopotentials
are available in the UDS (Soviet) and foreign literature. These bio-
electrical activity data pertain only to flight on military reactive
planes, for flights of short duration and have nothing to do with EEG
changes after long flights on passenger gas-turbine planes.
EEG's of ground workers, (e.g., engineers of Diesel engines and
locomotives), following prolonged (7 hours and longer) driving of the
engine, have manifested a drop in amplitude of the a rhythm, a decrease
in its frequency, as well as shortening of the period of reconstruction
of alpha-activity after light stimulation of the eye. The authors
(M. G. Babadzhanyan and A. M. Volkov) believe these changes indicate an
accumulation of fatigue with formation of stagnation phenomena in the
cerebral cortex.
Analysis of EEG data on the flight personnel, after long flights,
showed the following :
All members of the crew fully preserved the expression, quantity,
and periodicity of the a rhythm. Simultaneously, there occurred a drop
in voltage of the amplitude of biopotentials (a, p, and others). De-
creased amplitude, for instance, of cc waves, was within the limits of
10-25 microvolt, which was from Ik to 33 percent of the initial start-
ing figure .
373
Such EEG indexes as depression and latent and restoration periods
of the a rhythm after striking light to the eyes (or exposing eyes to
light) change in the sense of lengthening.
The EEG, taken after the flight, showed no essential changes in the
expression of slow waves. Insignificant increase in the number of such
waves was observed in 36.4 percent of the examined individuals. In
these cases, the amplitude of the waves was lowered, although their
duration remained constant. Restoration of EEG components during rest
occurred gradually, but not sooner than in 1.5-3 days.
The data show no EEG differences for the various flight professions
(captains of the airships, second pilots and pilots), nor for day and
night flights .
Analysis of changes in brain biopotentials for personnel perform-
ing long nonstop flights on gas turbine planes, leads to the conclusion
that there is a decreased bioelectrical activity of the cerebral cortex
and a decrease in neural mobility with prevalence of inhibitory proc-
esses which may be considered a result of CNS fatigue.
Dependence of the aforementioned changes upon fatigue is proved by
the time (1.5-3 days) required to restore EEG components during rest.
EEG changes, including changes in other physiological functions, permit
recommendation of standardization of after-flight rest periods.
FUNCTIONAL STATE OF THE VESTIBULAR ANALYZER DURING THE FIRST
FEW HOURS FOLLOWING IRRADIATION WITH DIFFERENT DOSES
A. V. Sevan 'kayev
The problem of the effect of ionizing irradiation upon vestibular
analyzer function is now assuming great importance. Under cosmic flight
conditions there is a possibility of functional shifts in the vestibular
analyzer, one cause of which may be penetrating irradiation.
Having at our disposal new techniques for quantitative evaluation
of the functional state of the vestibular analyzer and of radiation ef-
fect, we decided to collect relevant data during the first few hours fol-
lowing irradiation with various doses. (investigation was done under
the direction of Prof. M. P. Domshlak and Doctor of Med. Sciences Yu. G.
Grigor'yev.) The data obtained may be of use in developing measures to
guarantee normal functioning of the vestibular analyzer- -a requisite
under conditions of cosmic flight.
37^
Experiments were done on 120 rabbits with a new setup that permitted
adequate stimulation of the labyrinth and a wide range of angle accelera-
tions and velocities from the subthreshold and threshold to supra threshold
rates (Yu. G. Grigor 'yev, B. B. Blokhov, "New Apparatus for an Adequate
Stimulation of Vestibular Analyzer, Making Use of a Wide Diapason of
Angle Acceleration and Kryolis Forces (or powers) in Clinical and Experi-
mental Examination." Zhurn. "Vestnik otorinolaringologii, " No. 6, 196l).
Adequate labyrinth stimulation of practically any desired magnitude and
current -surveying rings permitted objective registration of the vestibulo-
somatic (nystagmus) and of some vestibulo- vegetative reflexes (frequency
of respiration and pulse). Subdivided into 6 series (20 rabbits in each
series), the animals were subjected to total irradiation in doses of 50,
100, 500, 800 and 5000 r. Evaluation was performed on the threshold
sensibility and reactivity of the vestibular analyzer to adequate stimu-
lation two or three times before, immediately following, and 2 and 5
hours after stimulation. Control and experimental animals were examined
at the same intervals .
The initial reactions of any analyzer to stimulation are functional
and are usually manifested by changes in sensitivity thresholds . The
table shows that in the series I and II of the experiments, i.e., after
irradiation with doses of 50 r and 100 r, 23 of the k-0 rabbits reacted
to the irradiation, 13 manifested lowered threshold sensitivity, and the
remaining 10 showed heightened sensitivity. Results obtained with the
"test for reactivity", i.e., after the use of gradually increasing ade-
quate stimulation ( 30, 60 and 120°/sec, with subsequent "stop- stimulus")
likewise indicate an increase in stimulation of the vestibular analyzer.
In the III series of experiments (dose, 500 r), l8 out of 20 rab-
bits reacted to irradiation and manifested the same type of reaction
with a tendency to inhibit the function of the vestibular analyzer.
The maximum drop of threshold sensitivity and reactivity was observed 2
hours after radiation. Five hours after stimulation, the analyzer's
reaction approximated the reaction in the control animals.
An increased dose (800 and 5000 r) resulted in still greater in-
hibition of analyzer function. Five hours after termination of radiation
The average rate for the duration of nystagmus (D Q ) which took place
in response to the "stop- stimulus" at the speeds of 30, 60 and 120°/sec,
D-D Q
was calculated according to the formula: D = , where D is
the duration of nystagmus for each rabbit before radiation, D is the
duration of nystagmus after irradiation in the corresponding period of
observation, n is the number of animals in series.
375
Changes in the Threshold Sensitivity of the Vestibular Analyzer
During the First 5 Hours Following Irradiation, in Each Series
of Experiments
Number of
rabbits
in series
Number of
rabbits
which reacted
to
irradiation
Nature of reaction
Number of
Dose in
roentgens
Lowered
threshold
sensitivity
Heightened
threshold
sensitivity
rabbits not
reacting
to irradiation
50-100
UO
23
13
10
17
500
20
18
18
-
2
800
20
20
18
2
-
5000
20
20
18
2
-
stimulation there was a tendency to restoration of the initial response
to stimulation.
After irradiation, particularly with doses of 300, 800 and 5000 r,
the animals revealed disturbances in the normal force ratios in the
vestibulo-vegetative reactions. Instead of the usual intensity and
duration of reaction in proportion to the increased growth of adequate
stimulation of the vestibular apparatus, there was observed a nearly
one-type pattern of changes in respiration in response to weak and
strong stimulations (compensating phase). In some animals, changes in
respiration occurred only in response to sufficiently intense labyrinth
stimulation (l20°/sec) and also, were less significant following than
before radiation.
In this manner, there has been established the range of irradiations
with doses of 5OO-5OOO r which results in disruption of functional state
of the vestibular analyzer in the sense of lowering its response to
stimulation and reactivity. Of great importance is the fact that, within
the dose range of 500 to 100 r, in some animals there was observed an
entirely different kind of functional change--increased response to
stimulation. As a practical measure, it is significant that irradiation
with 500 r an( i above suppresses not alone the vestibulo-somatic reflex,
but also the vestibulo-vegetative reactions, which reflects the lesser
probability of the appearance of corresponding disturbances in the
vestibular analyzer under the combined effect of ionizing irradiation
and adequate stimulation of the semicircular canals. The diverse ten-
dencies in the changes of the response to stimulation and reactivity
of the vestibular analyzer, with irradiation with lesser and greater
doses, leads us to assume prevalence of reaction, under these conditions,
in the different portions or functional mechanisms of the analyzer.
376
HISTOCHEMICAL EXAMINATION OF THE CHANGES IN THE DISTRIBUTION
OF THE EFFECT OF DEHYDROGENASE SUCCINATE, CARBOANHYDRASE,
ALKALINE AND ACID PHOSPHOMONOESTERASE, ADENOSINE TRIPHOSPHATASE
AND SULFHYDRYL GROUPS OF PROTEINS IN INNER ORGANS IN ACUTE
STATE OF OXYGEN STARVATION
S. N. Sergeyev
His to chemical studies of the changes in the activity of the fer-
ments in various organs and systems of the organism in hypoxia are in-
adequate. Various histochemical changes have been demonstrated in the
distribution of activity of succinate dehydrogenase and acid phospho-
monoesterase in different sections of the brain (Ye. Yu. Chenykayeva
(l96l), Kholle (1955), Baranskiy (1959), Appel', Nereanti and Markovitsi
(i960), Bekker and Barra (1961)), as well as alkaline phosphomonoesterase
in the liver and kidneys (Tsimmerman and Getslaf, 1961). The literature
shows no histochemical studies on the subject of the changes in distri-
bution of carboanhydrase, adenosine triphosphatase, or sulfhydryl groups
of albumins. However, it should be noted that in hypoxia there have
been demonstrated some changes in the activity of carboanhydrase in the
substance of the brain and blood, Ye. M. Kreps (±9k6) , V. V. Strel'tsov
and I. M. Khazen (1946), Ye. Yu. Chenykayeva (19V7).
The above-mentioned studies were done under relatively long-lasting
conditions (calculated in hours) while the organism remained under the
effect of decreased partial pressure of oxygen in the exhaled air. How-
ever, of great theoretical interest and of vast practical importance is
the revelation of the earliest possible structural shifts in the organism
caused by hypoxia. These are expressed in the reconstruction of the ac-
tivity of ferment systems which participate in the performance of
alkaline-reconstruction processes ( succinate dehydrogenase and carboanhy-
drase) in the organism and which play a prominent role in the dynamics
of the exchange (phosphatase). This, in turn, is of great importance
for the discovery of intimate mechanisms of the organism's reaction to
oxygen deficiency and, on the other hand, for the elaboration of methods
of early microscopic diagnosis of the state of acute hypoxidosis of the
tissues.
During the past few years, we carried on some histochemical re-
search- -using white rats with acute oxygen deficiency, produced by means
of lowering partial pressure of oxygen in the inhaled air, (during as-
cension in altitude chamber) --on the activity changes of the ferments of
oxydation and phosphorous metabolism (succinate dehydrogenase, carbo-
anhydrase, acid and alkaline phosphomonoesterase and adenosine triphos-
phatase), as well as sulfhydryl groups of albumin in certain inner
organs (myocardium, liver, kidneys).
377
For this investigation, we made experimental studies on the activ-
ity of the mentioned ferments, both in acute hypoxia, with fatal outcome
within a few minutes (with quick drop in "barometric pressure to 1^5 mm
Hg which causes the death of the organism within 3-5 minutes), as well
as with the animals in the altitude chamber with pressure of 183 mm Hg
during 10 minutes with subsequent sacrifice of the animal. Each experi-
mental animal had a control mate which was sacrificed by decapitation
at the same time as the experimental animal.
At autopsy, identical organs from the experimental and control
animals were mounted on the microtome table in one block and frozen
with solid carbon dioxide. This permitted obtaining a single section
from both identical organs from experimental and control animals, and
facilitated comparative investigation of the activity changes of the
ferment, excluding the influence of such factors as uneven thickness
of sections, the quality of the batch of reagent and other potential
changes, which elude exact evaluation but are capable of influencing
changes in the activity of the ferment in the section.
Sections of the fresh nonfixated tissues, 12 microns in thickness,
were prepared in the cryostat at T = -l8°C, and were laid on object
glasses. Examination of the activity of succinate dehydrogenase was
done with nitro-ST after Nakhlas (1957), carboanhydrase after Kurata
(l953)j in Khoysler modification, acid and alkaline phosphomonoesterase
with (3-glycerophosphatase after Vakhshteyn and Meyzel ' (1957)- Exami-
nation of the sulfhydryl groups of albumins was done with DDD and diazol
black K after Barnet and Zeligman (1952). Control sections with reac-
tion to succinate dehydrogenase, acid and alkaline phosphatase and
adenosine triphosphatase were incubated without substrate, with reac-
tion to carboanhydrase- -in the presence of acetozolamidej with reaction
to sulfhydryl groups, blocking was accomplished with monobrom acetic
acid. To obtain survey specimens, the sections were stained with hema-
toxyline eosin and scarlet red for fat. Under microscopic examination
of the specimens, the qualitative changes were studied in the localiza-
tion of the ferment, as well as in a series of cases which received
quantitative evaluation of the changes in the activity from the data of
measurements of the relative optical density of the sections with the
histophotometrical method.
Microscopic examination of the experimental animals has demonstrated,
in most of the cases, a certain depression in the myocardium of succinate
dehydrogenase activity, preeminently in the middle layers of the myo-
cardium. In the liver of most of these animals there was observed con-
siderable inhibition of the activity of this ferment, mostly in the
central portions of the lobule; in some of these, along the periphery
of the lobules, around the septal veins, groups of cells were found
with a marked increase in ferment activity. No changes were noted
378
in the activity of this ferment in the kidneys, although in some there
was seen a poorly expressed decrease in the deposits of formasine.
With the reaction to carboanhydrase , a considerable increase in the
activity of carboanhydrase of the myocardium was generally observed. In
the overwhelming majority of these animals there occurred sometimes con-
siderable inhibition in the activity of liver carbohydrase. In a number
of cases, it was possible to observe some inhibition of the activity of
the carboanhydrates in the proximal portions of the convoluted tubules in
the kidneys, and occasionally there was seen increased deposits of sedi-
ment in the epithelium of single isolated convoluted tubules in the dis-
tal portions.
No changes were found in the activity of the ferment, acid phospho-
monoesterase, in the myocardium. In the liver, in the overwhelming ma-
jority of cases, considerable inhibition of the activity of the acid
phosphatase was observed, mostly at the expense of decreased sediments
in the cytoplasm of the parenchymatous cells. In the kidneys of the ex-
perimental animals, in a number of cases, a certain diminution of activ-
ity of the ferment in question was revealed in the epithelium of the
convoluted tubules.
Investigation of the changes in the distribution of activity of the
alkaline phosphomonoesterase showed, in some cases, a uniform decrease
in sediments in the muscle fibers of the myocardium. However, the walls
of the finer blood vessels and intermuscular capillaries showed high de-
gree of activity of the ferment. In the liver of these animals, against
the background of general relative decrease in sediments in the central
portions of the lobules of the liver, a marked increase was observed in
the activity of the ferment in the cells and in the walls of the capil-
laries along the peripheral hepatic lobules around the septal veins. In
the kidneys, in single isolated observations, there was noticed indis-
tinctly expressed uniform decrease in the activity of the given ferment.
In studying the changes in the activity of the adenosine triphos-
phatase, in a small number of cases, some decrease was seen in sediments
in the sarcoplasm of the muscle fibers of the myocardium. The activity
of the ferments in their nuclei, as well as in the walls of smaller
blood vessels and intermuscular capillaries, remained on a high level.
In the liver, in a number of cases, there was noted a considerable
slackening of the activity of the given ferment in the cytoplasm of the
parenchymatous cells. In the kidneys of these animals no definite
changes were revealed in the degree of activity of the adenosine tri-
phosphatase as compared to the control animals.
In examining the sulfhydryl groups in the myocardium, liver, and
kidneys, no marked changes were discovered in the staining of the tissue
elements; as a rule, an intense blue staining was observed in the
379
majority of structural elements of the organs (double combination), indi-
cating a high concentration of the sulfhydryl groups in the tissue pro-
teins .
In the sections, stained with hematoxyline eosin and scarlet red,
no morphological changes were seen.
It should he noted that in the dead animals, the mentioned changes
in the activity of the ferments varied only in the degree of intensity.
In this manner, experimental study of the changes in the activity
of the succinate dehydrogenase, carboanhydrase, acid and alkaline phos-
phomonoesterase, and adenosine triphosphatase showed typical peculiari-
ties in distribution of the ferments of the oxidizing and phosphorous
metabolism in acute hypoxia, which are already to be seen during the
first minutes and which consist, as a rule, of a certain relative inhi-
bition of the activity or (which is true of the carboanhydrate of the myo-
cardium) its intensification or, finally, in its dissemination among the
various functional structural formations within the same organ (as in
the case of the carboanhydrase in the kidneys) . On the other hand, it
has been demonstrated that histochemical changes in the activity of the
ferments develop much earlier than the changes in other important bio-
logically structural components of the tissue of the organs under study--
the sulfhydryl groups of proteins .
Experimental data indicated an extremely rapid reaction, on the
part of the ferment systems of the organism, to the disruption of the
oxygen supply. These data may be useful in differential microscopic
diagnosis where death is due to acute hypoxia.
CONTEMPORARY PROBLEMS IN AVIATION PHYSIOLOGY
N. P. Sergeyev, V. A. Sergey ev and F. P. Kosmolinskiy
Plying, under severe conditions, differs considerably from any
other mass profession and involves a number of specific traits.
The main characteristic of flying is tension--in the nervous and
emotional sense. Tension is reflected in all of the pilot's behavior
and in the functional state of his basic physiological systems .
The pilot's work is characterized by a definite goal and an exertion
of will that results in sthenic type reactions. At the same time, flying
not infrequently is associated with negative emotions.
111 ii inn
380
It has been established that nervous and emotional tension in the
pilot increases when flying planes with high flight tactical data, and
when adjusting to new type places and new complex flight missions (N. P.
Serge yev, A. A. Vorona, N. A. Agadzhanyan, D. V.Abayev, V. G. Kuznetsov
and others) .
The same level of energy expenditure in a pilot and in some repre-
sentative of any other profession with average physical load — for an
equal period of working time--will cause, in the pilot, considerably
greater physicobiochemical shifts, caused not by the physical load but
by the stress reaction (N. P.Sergeyev, D. I. Ivanov and others, i960,
V. M. Vasyutochkin, I961) .
These shifts, first of all, occur in the vegetative vascular reac-
tions and in the mechanisms of neuroendocrinal regulation. Hyperactiv-
ity in the flier's organism, which does not correlate with the effect of
physical factors of the flight, results in a peculiar state of super -
compensation of the physiological shifts. A characteristic picture ap-
pears of adaptation syndrome under the conditions of intensified activity
of the subcortical processes and inductive inhibition of the regulating
functions of the cerebral cortex. The attendant hyperf unction in the
hypothalamus hypophysis suprarenals results in a prolonged after-effect
which camouflages and distorts both the physiological processes of adap-
tation of the organism to special factors of the flight, and the appear-
ance of fatigue processes.
Nervous and emotional tension in flying influences basic physiologi-
cal processes, and not infrequently promotes "stagnation" phenomena and
under unfavorable conditions. If repeated many times, it may be the
cause of a number of pathological processes, such as atherosclerosis and
hypertonia. Many research workers emphasize the apparent association of
obesity and atherosclerosis in fliers, not so much from nutritional
errors, as from occupational nervous and emotional tension (0. Koldobski,
P. Novak, F. Varel, i960, V. M. Basyutochkin, 1961) . On autopsy material,
V. G-lentts and V. Stembridge, 1959 3 a ^d F. Vorel, 1961, have shown ather-
osclerotic changes in 70 percent of the flight crew, including young
pilots.
In our studies (F . P. Kosmolinskiy, V. A. Sergeyev, I. M. Khazen,
I96I-I962) we established a correlation between the degree of nervous
and emotional tension during flight and the development of obesity among
the flight personnel (various groups of fliers, with the same nutritional
intake, but carrying different flight loads and with different flight as-
signments have been examined) .
Comparison of data on cardiovascular disease for different profes-
sional groups (materials from the Institute of Public Health and History
of Medicine, N. A. Semashko Memorial, 1961) and flight personnel (L. S.
381
Isaakyan, 1962, personal observations) leads to the conclusion that there
exists a definite relationship between cardiovascular pathology and the
professional activities of fliers.
Unquestionably, the great nervous and emotional tension accompanying
flights increases heart activity, and necessarily affects the cardiovas-
cular system. Thus, some typical EKG changes, discovered among a flight
crew performing intensive flights, were apparently of emotional origin:
increased voltage of the R and T waves in all leads, peculiar steep rise
of the S-T interval in the second lead, and others (P. V. Buyanov, S.Ye.
Komshalyuk, F. P. Kosmolinskiy, 1962) .
The same holds true for the various biochemical changes the flier
experiences under nervous and emotional tension: cholestrinemia, in-
creased production of steroid hormones, and elimination of ascorbic acid
from the organism (G. A. Arutyunov, Yu. F. Udalov, I. S. Balakhovskiy,
N. A. Vorob'yev, I. G. Dlusskaya, I. M. Khazen, F. P. Kosmolinskiy and
others) .
The second special feature is that aviation progress has changed
flying from a mental and physical activity to one that is more and more
purely mental.
Improvements in the tactical qualities of planes have eliminated
much of the pilot's muscular activities and substituted automatic and
semi-automatic flight control equipment, such as booster systems, servo-
units, and amplifiers.
Technical development, by placing in the pilot's cabin more and
more new aggregates, semi-automatic observation gadgets, radio equipment,
and control apparatus, has made the work of the flier nearly equal to
that of the operating engineer. The system of pilot training has changed
and new professional requirements have arisen to meet the needs of com-
plex aviation technology.
The complex equipment in the pilot's cabin, theoretically intended
to facilitate the work of the operator and, unquestionably, improving
his armature, at the same time has its disadvantages: great flow of in-
formation from the indicators, need of constant control over the work of
the semi-automatic equipment, piloting of the plane, control of the
motor and a number of aggregates --all these create overloading of CNS
and analyzers, particularly the visual analyzer. Constantly increasing
speed reduces the time available for pilot reactions, and may cause
errors of navigation. Thus, I. A. Kamyshev estimates that, during the
most crucial part of the flight, the pilot's eye travels with great
speed over the apparatus, fixating up to 200 indications per minute.
This allows insufficient time for the mental evaluation of a quickly
changing environment and for definitive decisions. Consequently, the
382
work of the pilot skirts the edge of the nervous system' s physiological
li mi ts.
The third requirement of flying is working under the dynamic factors
of flight (acceleration, overload, noise, vibration) and the unusual hy-
gienic conditions posed "by the limited space of the cabin, special equip-
ment, fixed position of the body in the seat and oxygen respiratory appa-
ratus .
Associated with these requirements of flying are the problems of
aviation physiology pertaining to facilitation of work, prophylaxis of
professional pathology, and improved performance of the flier.
Along with these conditions, common to flying, there are require-
ments peculiar to each type of plane, the nature of flight assignment,
and the functional duties of the crew members. Thus, there is a need to
draw up recommendations for improving the organism's capacity to resist
the unfavorable factors of flying.
These changing conditions of flying and the complexity of maintain-
ing them at optimum level require the combined efforts of physiologists,
public health specialists, hygienists, psychologists, and such other spe-
cialists as engineers and architects.
Aviation medicine is commonly subdivided into disciplines like avia-
tion physiology, hygiene, psychology, and medical flight experts. The
time seems now ripe for discussion of a new, quite independent department
of aviation medicine — the physiology of flight work. Like physiology of
labor, the physiology of flight brings together a number of sciences.
It studies the effects of the organism' s encounter with flying and its
capacity for work and fatigability and individual behavior traits under
flying conditions.
At present, these basic problems in flight physiology have assumed
great scientific and practical interest. Scientists are seeking to de-
velop methods of increasing the flier's resistance to the damaging ef-
fects of flying, and to normalize and organize his work conditions.
Aviation medicine deals with problems of rationalization of labor
in the "pilot-airplane" system, and with the problems of engineering
psychology, a new discipline with the methods of psychology, cybernet-
ics, and bionomics. In our day, it has become quite obvious that in
constructing machines for efficient operation by man, it is necessary
to consider not only man's anatomy and physiology, but also his psychol-
ogy.
The problems of creating technical means of pilot defense against
injurious factors and of removing the physiological limits of flight
383
tolerance are solved jointly by constructing engineers, contractors, and
hygienists, with the essential participation of aviation medicine
specialists.
Changes in the conditions of flying have stimulated a need for new
methods of investigation. No longer effective are such formerly impor-
tant methods as chronometrical timing of operations, calculation of en-
ergy expenditures, determination of caloric content of the food ration.
Under contemporary conditions , methods of studying the flier ' s
higher nervous activity and his personal "behavioral traits, assume par-
ticular importance. It is necessary to establish the level of nervous
and emotional tension, the degree of difficulty in the performance of
the flight mission and evaluation of reserve potentialities of the or-
ganism.
If formerly it was possible to judge the degree of physical diffi-
culty of a job, from certain vegetative changes (pulse frequency and
respiratory movements) , at present such changes are successfully used as
criteria for evaluating nervous tension and emotional excitability dur-
ing flight. Physiologists, studying flying fatigue, find it necessary
to gain a differential approach to the data obtained in physiological
investigation, depending upon the nature of the work performed, individ-
ual psychophysical peculiarities of each flier (the type of higher nerv-
ous activity) and his attitude to his work.
From the practical standpoint, it is important to study fatigue and
capacity to work from the special traits and signs manifested in the
course of basic CNS nervous processes (phase conditions) , both during
and after flight. Schedules of work, rest, and nutrition must be studied
if a high level of work capability is to be maintained. Along with de-
termination of optimal intervals between flights, an extensive elabora-
tion of methods for restoring work capability is needed, in association
with study of the dynamics of physical condition, tension mechanisms,
and occupational diseases among the aviation crew. At the same time, ex-
perts in the field of aviation physiology must provide recommendations
for a rational approach to regulation of schedules of work, rest and nu-
trition, intelligent operation of special equipment and oxygen supply,
general and special physical training and supervision of health.
The problem of pilot work capability is closely associated with
problems of improving resistance of the organism to extreme flying condi-
tions. This may be achieved both with specific methods of training (for
the effect of some concrete factor in flight, like overloading) , and
with nonspecific methods that influence the homeostatic mechanisms of
the organism.
38U
Improvement of the organism's resistance to modern flying condi-
tions requires new nutritional products which possess the properties of
physiological stimulation and normalization. In view of the enormous
influence of the qualitative composition of the food upon nervous proc-
esses, nutrition in flight should he studied again with the object of
increasing the specific weight of foods which include some full -value
proteins and highly unsaturated fatty acids . It is also necessary to
review vitamin content and the place of salts and microelements in nu-
trition. The substances assimilated by the organism should provide the
most favorable biochemical conditions for the higher CNS processes.
Some new forms of rations on board should be prepared on short order.
The physiology of flight work, being physiology of activity and
work behavior, includes study of the problems of muscular activity of
the flier (motor reactions in response to received information, coordi-
nation of movements, static and dynamical loads, etc.), which, in turn,
is closely associated with increasingly important problems of physical
training of the pilot.
For successful development of an extensive plan of work in the
field of flight physiology it is necessary to consider the selection and
perfection of the methods of examining the flight personnel. It is neces-
sary to put into practice in experimental work, complete examination of
the flight personnel by clinical, physiological, biochemical and psycho-
logical methods, including the dynamics of the processes studied and in-
dividual differences among fliers. At the same time, some uniformity
should be attained in the methods and standardization of examining equip-
ment, .so that the study of flying may be carried out on a wide scale.
In this manner, under contemporary conditions, the need arises for
extensive research in the field of aviation physiology. This consti-
tutes a special division in aviation medicine and physiology of labor-
that of physiology of flying.
THE ROLE OF REDUCED REACTIVITY OF THE ORGANISM IN RESISTANCE
TO EXTREME INFLUENCES (ACCELERATION, RADIATION)
N. N. Sirotinin
The best example of lowered reactivity among mammals is that which
occurs during winter hibernation (N. N. Sirotinin, 193^, 1939)- It has
long been known that, while in deep winter hibernation, animals better
tolerate hypoxia (Paul Bahr, 1878, N. V. Kravkov, 1903, N. N. Sirotinin,
385
19 to, N. A. Alkhangel' skaya, 19^9) , as well as a number of other patho-
gens (intoxication by various poisons, in particular, bacterial toxins).
Research on the effect of winter hibernation on resistance to trans-
versely directed radial acceleration was first done in 19^6. It was
found that bats, hedgehogs, marmots, and hamsters will tolerate much
greater accelerations during deep winter sleep. Bats showed the great-
est tolerance.
Tolerance of acceleration depends upon the depth of sleep; in the
spring, before awakening, it is reduced and approaches that of the state
of waking. Because of reduced reactivity in the hibernating animal, ac-
celeration produces no great degree of changes in circulation and respi-
ration — except for marmots, which do show increase in cardiac function
and respiration, the latter occasionally even stopping, although this
does not result in death.
Increased resistance to acceleration during winter hibernation is
associated, first of all, with increased resistance to hypoxia, as demon-
strated with radial acceleration in our laboratory by E. 0. Teplitskaya
(19^6-1959) , and others (Neis, Idel'berg, Charlend, Rozenbaum, 195 1 *-,
A. A. Sergeev, 1957, E. A. Kovalenko, 1963) • Discovery of hypoxia of
the brain with this effect was later confirmed in our laboratory by I. F.
Sokolyanskiy. We observed increased resistance to radial acceleration
in rats adapted to hypoxia in an altitude chamber, and in mice, rats,
and guinea pigs acclimated to high mountain temperatures.
V. I. Danileyko (1958, 1959), in our laboratory, found that hypo-
thermia in rats results in increased resistance to radial acceleration;
this was confirmed by A. A. Sergeev, 1957, and G. D. Glod, V. S. Oganov,
W. N. Timofeev, 1962. S. Troyan and L. Ilek (1961) observed increased
resistance to acceleration during ontogenesis in rats under the influence
of pentobarbital and chlorpromazine. The obtained rates of resistance
vary with different authors, and, apparently, depend upon the degree of
hypothermia: the deeper hypothermia, the greater the resistance to ra-
dial acceleration.
■V. I. Danileyko (1958) discovered that barbamil narcosis will cause,
in rats, a certain increase in resistance in rats to the effect of accel-
eration.
Comparison of the various influences of increased resistance to ac-
celeration shows deep winter hibernation to be most effective, followed
by deep hypothermia, and, least effective of all, narcosis.
The literature contains numerous references to increased radio -
resistance, resulting from different forms of hypothermia, but much less
data on the increase of such resistance during winter sleep. Our
386
research, carried out with E. I. Chayka (1959) > shows that deep winter
hibernation increases radioresistance more than does hypothermia. On
the basis of the obtained data (1957, 1959) > w e may assume that animals
during winter sleep and deep hypothermia are suitable objects for inves-
tigation during prolonged and remote cosmic flights. Some of our new
data once again confirm this assumption.
SOME NEW INDEXES OF HEMODYNAMICS, OBTAINED BY MEANS
OF THE MECHANOCARDIOGRAPHIC METHOD
M. N. Syviritkin
The flier, under conditions on contemporary planes, experiences a
number of unusual factors which impose extremely great demands on the
cardiovascular system. In this connection, an improved and more detailed
evaluation of the circulatory condition of flying personnel by the medi-
cal flight commission hospital becomes of great practical importance.
Existing methods of medical flight specialization still do not furnish
complete knowledge of the functional condition of heart and blood vessels.
Determination of the duration of the various phases of cardiac ac-
tivity by EKG, phonocardiograms , ballistocardiograms, electrokymograms,
and other devices is unquestionably valuable, but still does not offer
sufficient quantitative knowledge of the strength of heart contractions.
The volume speed of blood outflow from the left ventricle into the aorta
(VSO) was used in evaluating the strength of myocardial contractions in
dogs by I. P. Pavlov back in 1883-1887, but no VSO studies have yet been
done on man. (This perhaps could be explained by the absence of proper
methods for simultaneous registration of systolic heart volume and time
of expulsion.) Now, however, popularization of" the mecharjo:-ardiographic
method of Prof. N. N. Savitskiy, permits evaluation of both VSO and the
power of contractions of the left ventricle.
As we know, simultaneous registration of tac-ho -oscillograms and
spliygrnograms by mechanocardiographic means permits determination of im-
portant hemodynamic indexes sucn as: arterial pressure, systolic and
minute volume of circulating blood, time of expulsion, speed of propaga-
tion of pulse wave along the vessels, and peripheral resistance. Know-
ing the value of the systolic volume (CV in cm^) and the expulsion time
(t in seconds), we can calculate the volume speed of blood expulsion
into the aorta. The VSO represents the quotient from the division of CV
*y t.
387
CV o,
VSO = rr- cnP/sec.
The rate of the values of VSO and average hemodynamic pressure (My)
permits calculation of the strength of the contractions of the left ven-
tricle (P).
Strength (P) is a unit, measured by work (A), performed during a
unit of time (t) , for instance, in 1 second. Hence, the formula for
strength of contractions of the left ventricle is expressed as:
a cv
P = ~ = ^L -My = VSO-My watt.
Under conditions of basal metabolism, we determined the strength of
contractions of the left ventricle and the volume speed of expulsion
(outflow) of blood for 150 trained and 150 non -trained healthy individ-
uals, ages 19 to 25 years. Average rates for both items proved to be
practically identical for both groups: P = 2.6U to 2.65 watt and VSO be-
ing 253 cnP/sec, respectively. However, the non-trained individuals
showed greater variations in rates than did the trained ones. Thus, for
VSO in the trained, a amounted to h^>, m - 3-6, and in the non -trained,
a was 57, m = k.7. The two indexes in patients with neurocirculatory
dystonia of the hypertensive type proved higher than in the normal indi-
viduals .
Studies on the volume speed of blood expulsion into the aorta and
the power of contractions in the left ventricle in healthy persons and
in a number of pathological states, carried out in combination with the
general clinical methods of investigation, have shown the great impor-
tance of these hemodynamic factors in evaluating myocardial contraction.
Introduction of the two hemodynamic indexes into the practice of special-
ized flight medicine will permit more expert decisions.
METABOLIC CHANGES UNDER THE EFFECT OF PARACHUTE JUMPING
Yu. K. Syzrantsev, Yu. F. Udalov and N. A. Chelnokova
Flying personnel, in mastering life saving techniques, periodically
perform parachute jumps, since preparation for the jump and the jump it-
self are associated with considerable nervous and emotional tension.
388
To determine the effect of this tension, we studied the influence
of parachute jumping on certain aspects of metabolism, utilizing individ-
uals of varying experience in parachute jumping. We studied expenditure
of energy and indexes of protein metabolism and metabolism of vitamins,
and determined the cholesterine and nucleic acid content in blood.
These facts have been established: (l) changes in metabolism re-
sult not only from the parachute jump itself, but occur long in advance
of the jump, as a consequence of nervous and emotional tension; (2) an
increase (by 17-22 percent) of gas exchange (gaseous metabolism) begins
immediately following the order to jump and lasts throughout the entire
interval preceding the jumping.
The data characteristic for the gas exchange are summarized in
Table 1.
Table 1. Changes in Certain Indexes of Protein Metabolism
Associated with Parachute Jumping
(2k hour indexes)
Elimination from the organism
of the terminal products of
protein metabolism
Total
nitrogen
Nitrogen
urea
Nitrous
ammonia
Control
On the days of parachute
jumping
On the days after jumping
9-3
11.0
10.6
^•53
6.0
5-52
O.^k
0.73
0.59
These data clearly demonstrate: (l) increased elimination of total
nitrogen and nitrogen urea on the day of jumping and on the day follow-
ing the jump, and (2) the intensified protein metabolism consequent to
the great emotional and physical load to which the organism is subjected.
The increased Gosselbach coefficient (the nitrogen ammonia and total ni-
trogen ratio) during the same 2k hours when the jumping took place indi-
cates qualitative changes in the protein metabolism, as well as consider-
able nervous and emotional tension. (Ammonia, as we know, increases
during nervous excitement.) Increased nitrogen elimination was noted
also on days when scheduled jumps were cancelled- -again reflecting the
significant role of emotions and pointing to the conditioned reflex char-
acter of metabolic changes.
389
Many investigators believe that physiological tension produces
changes in protein metabolism, characterized by a lowered resynthesis
of protein. However, since urea elimination on jumping days did not in-
crease, it may be assumed that increased decomposition of nucleic acid
does not take place. It should be noted, however, that the blood nucleic
acid content, on the day of the jump, dropped to 280 mg percent, as com-
pared to 36O mg percent on the day of control.
Results indicate that changes in protein metabolism during the para-
chute jump training are similar to those manifested under conditions of
prolonged flight. Studies on vitamin metabolism during parachute jump-
ing have shown that the organism has a greater need for vitamins at that
time.
Data on excretion of vitamins for 2k hours are given in Table 2.
Table 2. Changes in Rates of Vitamin Metabolism
Associated with Parachute Jumping
Elimination of urine in 2k hrs
Vitamin
B l
Hg
Vitamin
B 2
Hg
N-l -methyl -
nicotinam-
ide, mg
U-Pyridoxic
acid,
l-ig
Control
(2k hrs without jumping)
On the days of parachute
jumps
On the days following the
jumps
350
230
270
kk
37
30
1.9
1.0
1.3
450
395
490
A drop in the indexes of vitamin metabolism indicates not only an
increased vitamin requirement but also a marked emotional tension on
jumping days. It is important to emphasize the greatest changes were
found in metabolism of vitamin B-, — the vitamin which participates di-
rectly in transmittal of nervous stimulation, and in nicotinic acid ex-
change, which is closely associated with CWS function.
Another index with prognostic significance is the blood cholesterol
content. Increased blood cholesterol was observed not only on the day
390
of jumping, "but also on the following day. From a prognostic standpoint,
increased blood cholesterol, especially against the background of altered
vascular tonus, is considered a forerunner of atherosclerosis.
VITAMINS IN THE DIET OF AVIATORS AND ASTRONAUTS
Yu. F. Udalov
Solution of the problem of establishing norms for the amounts of
basic nutrients, including vitamins, in the diet of aviators and astro-
nauts is of great practical and theoretical importance.
Dietetic requirements currently established for the population of
the USSR, including vitamin requirements, are based mainly on the calcu-
lation of energy expenditures. At the same time, it is extremely impor-
tant to determine in what ways the body's requirement for nutrient sub-
stances, including vitamins, is changed by nervous tension or other
unfavorable environmental factors which do not substantially alter the
level of energy expenditure .
The problem has arisen out of technological progress in industry,
transport, agriculture, and military science, which has reduced the num-
ber of professions involving high energy expenditures while at the same
time gradually increasing the number of workers in automated industries
who are engaged in control of industrial processes or adjustment of
machines and assemblies.
These professions include the work of aviators and astronauts,
whose activity involves considerable neuropsychiatric tension and the
effect of numerous external environmental factors on the organism. The
level of energy expenditure for aviators and astronauts is low and pre-
supposes a low vitamin requirement if the calorie requirement of the
diet is taken as a basis for calculation.
Examination of a large number of flight personnel completely con-
tradicts this supposition. The results of mass examinations of flight
crews disclosed a decrease in the amounts of vitamins B-i , Bo, Bg, C, and
occasionally PP available to the body, although the amounts of these
vitamins present in the diet corresponded to the established normal re-
quirements of the body for the energy expenditure involved. These data
led to the assumption of an increased vitamin requirement for aviators .
391
From the examination of various groups of flight personnel it has
been successfully established that the body's vitamin deficiencies are
more serious when flight activity is more intense. Thus, other condi-
tions being equal, the indexes of vitamin metabolism are more favorable
in pilots of propeller -driven aircraft then in jet pilots. An analogous
relationship was discovered in the examination of flight personnel fly-
ing a single type of supersonic aircraft, where one group was making
test flights and the other was making ordinary flights.
A comparison of the biochemical indexes of vitamin metabolism is
given in the table.
Indexes of the Metabolism of Vitamins B, , Bp, B^, and PP
in Different Groups of Flight Personnel
Test pilots
Pilots
Amount excreted in the urine
Vitamin B-,,
M-g
13 ± 1.0
197 ±9-0
Vitamin Bo,
Hg
52 ± 9.k
192 ± 6.2
^-Pyridoxic
acid,
mg
1300 ± 120
917 ±11.1
N-, -methyl -
nicotinam-
ide, |ag
6.76 ± 0.7
12. ^ ± O.98
Only the vitamin B^ (4-pyridoxic acid) metabolism index showed no
changes proportional to the nervous and emotional stress of flight activ-
ity. For vitamins B, , B , and PP the relationship is shown clearly
enough .
The basic element in the professional activity of- the aviator is
flying. Study of the effect of different types of flight missions on
the body' s vitamin metabolism has established that vitamin consumption
is substantially higher on days when flights occur. It is important to
note that regularly scheduled flights lead to a gradual increase in vita-
min deficiency, which can be avoided either by scheduling considerable
intervals between flying days, or by means of regular vitamin enrichment
of the flier's diet.
The bodily requirements of aviators are also dependent on the effect
of climatic factors. Other conditions being equal, the indexes of
392
vitamin metabolism were lower among flight personnel of units stationed
in extreme climatic zones (subpolar regions, the Arctic, and the far
south) than among personnel stationed in the temperate zone. The in-
creased vitamin consumption is the result of physiological stress, espe-
cially that due to acclimatization.
Numerous experiments have shown that a number of factors encountered
by the aviator or astronaut in flight have an effect on vitamin metabo-
lism in the body. Vitamin consumption increases during exposure of the
body to vibration, prolonged accelerations, or increased ambient temper-
atures. Vitamin requirements increase at high altitudes even when the
partial oxygen pressure of the respired air is maintained at the normal
level. The body's vitamin requirements are substantially increased un-
der conditions of strict isolation. Vitamin consumption is increased
during testing of emergency lifesaving gear and also during parachute
jumps.
In principle, the single type of reaction of the body to various
kinds of physiological and mental effects makes it possible to assert
that the basic factor which increases the vitamin requirements of avia-
tors and astronauts is the state of physiological stress.
Of practical importance to space flight is the specific increase of
the body's vitamin B/- requirement in response to vestibular stimulation
(short periods of weightlessness). Pyridoxine is also an important pro-
phylaxis against vestibular dysfunctions. This need for increased vita-
min content in astronaut rations was realized on the first space flights.
Thus, the astronaut's diet must be enriched with vitamins during the
period of training and especially during flight.
The significance of vitamin enrichment of the diets of aviators and
astronauts goes substantially beyond prevention of vitamin deficiencies.
First of all, vitamin enrichment is a means of increasing the body's re-
sistance to unfavorable environmental factors, infections, and the like;
it results in increased work capacity and reduces fatigue.
Vitamins have a normalizing effect on several metabolic indexes
which are affected by flight. Of especially practical importance are
data on the positive effect of vitamins on lipoid metabolism and partic-
ularly on cholesterol blood levels, significant in the prevention of ath-
erosclerosis among flight personnel. In addition, systematic vitamin en-
richment is also a practical measure directed at lowering the incidence
of illness and work loss among flight personnel.
On the basis of numerous experimental studies it has not only been
possible to establish the role and significance of vitamins under various
conditions encountered in the activity of aviators and astronauts, but
393
also to establish the actual amounts required by the body. The laws
which have been discovered governing vitamin metabolism under conditions
of physiological stress, and the resulting recommendations, are not ap-
plicable solely to flight personnel and astronauts. They can be extended
to other professional groups having similar working conditions, and to
military personnel.
CHANGES IN EXCITABILITY AND LABILITY OF THE VISUAL ANALYZER
UNDER CONDITIONS OF PROLONGED NONSTOP FLIGHTS
IN MULTIPASSENGER TURBOPROP PLANES
A. I. Ustinova
In studying the excitability and functional motility of the visual
analyzer during flight work, we will take as a point of departure N. Ye.
Vvedenskiy' s concept of the parabiotic process as the general reaction
of the living substrate to external stimulation, and of the general mech-
anism in the organism of neural regulation, on which the lability of
nervous centers is based.
Excitability and lability of the visual analyzer --quantitatively
measured by the level of electrical sensitivity- -maximum perception of
rhythmic optical and electrical fluctuations per unit of time, and dura-
tion of after -reactions (negative after-image and its latent period)
have been studied for many years. These studies have shown the limited
adequacy of changes in these indexes resulting from flight stress, work
done, type of aircraft, and other factors — changes which we have used as
the physiological basis for scheduling work and rest periods for passsen-
ger airplane pilots. The total effect of all flight factors on the CNS
as a whole results in the development in flight crew members of phase
states of visual analyzer excitability and lability during the course of
8- to 9-hour flights. This is manifested in the different direction of
changes and the degree of negative shift in the 3rd to kth and 8th to 9th
hours of flight.
During the first 3 to k hours of flight most members of the flight
crew showed either an increase in these indexes or maintenance at ini-
tial (takeoff) levels. In the 8th to 9th hours of flight (before land-
ing at the terminal airport, the basically prevailing observations (in
up to 77 percent of the investigations) were lowering of the indexes of
excitability and lability of the visual analyzer and an almost two -fold
increase in the degree of negative shift of several indexes. These
phases we have interpreted as different stages in the development of
39±
fatigue: the first corresponds to the period of "becoming accustomed to
the rhythm of activity or breaking-in period, and the second to the de-
terioration state (fatigue) (W. Ye. Vvedenskiy (l886) and others).
During the postf light rest period at the terminal airport (Khaba-
rovsk), which lasted 2k to 27 hours under dispensary conditions, resto-
ration of functions to initial level occurred in the majority of the
subjects, although obviously this restoration was not quite stable,
since the dynamics of change in function on the return leg (Khabarovsk- -
Moscow) showed a less clearly expressed positive phase in the 3 r & "to 4th
hours of flight and the degree of reduction of the visual analyzer func-
tions studied was much greater at any given stage of the flight. It
should be noted that the rapid change in time zones (totalling 7 hours)
and the consequent disruption of the habitual sleeping -waking and ali-
mentary rhythms of the passenger airplane pilots had an effect on the
quality of the rest period; the effect of the latter is confirmed by
data on sleep movements.
The dynamics of change in excitability and lability of the visual
analyzer during 8- to 9-hour flights we have observed, agree with the
shifts in flight dynamics obtained during studies of maximum muscle
power and static tenacity, half maximum strength of the right wrist, and
also during psychological investigations of the scope, concentration,
and distribution of attention.
The identical tendency of these changes assures us that all are
based on a single process — fatigue of the CNS.
Analysis of the research data made 1 to 1.5 hours after landing,
when the nervous and emotional stress of landing is subsiding, show that
in most subjects (up to 77 percent) changes in function are in the direc-
tion of decrease from the initial level (based on investigations made af-
ter 2 to 3 days of rest) . The degree of decrease of individual indexes
is from 69 percent to 112 percent. It was also discovered that in flight
commanders, negative shifts were more pronounced than in the remaining
members of the flight crews, and that night flights of equal duration
led to more intensive decrease then daylight flights.
Comparison of these data with similar data obtained after 8-hour
flights on various aircraft with gas turbine engines showed no essential
difference in the incidence or degree of negative changes. However, the
degree of decrease in indexes following 8- to 9 -hour nonstop flights in
multipassenger planes significantly exceeded similar shifts we obtained
among members of the crews of IL-18 aircraft following a normal daily
flight load (6 to 7 hours).
The above -described studies of excitability and lability of the vis-
ual analyzer under conditions of prolonged nonstop flights in
395
multipassenger turboprop aircraft have provided, besides other data, a
basis for working out and putting into effect practical recommendations
for the establishment of work and rest norms for flight crews.
SOME METABOLIC INDEXES IK THE ASTRONAUTS YU. A. GAGARIN,
G. S. TITOV, A. G. NIKOLAYEV AND P. R. POPOvTCH
T. A. Fedorova, L. T. Tutochkina, M. S. Uspenskaya,
M. M. Skurikhina and Ye. A. Fedorov
Examination of astronauts, by a special combination of analyses,
before and after flight on spacecraft has provided definite data on bio-
chemical changes occurring under such conditions. Biochemical tests
were chosen which show significant deviations from the norm in "stress"
states and under the effects of ionizing radiation.
The study of several radiation-sensitive biochemical indexes was of
interest, inasmuch as it may be possible, during future prolonged flights
traversing zones of dangerous radioactivity, to differentiate the bodily
changes caused by radiation from those caused by other space flight fac-
tors.
Method of Investigation
Biochemical blood and urine studies were conducted on astronauts un-
der hospital conditions, following intensive training and after rest per-
iods, and at the spacedrome before space flight and after return to the
earth (for a period of several days).
These blood studies consisted of refractometer determination of:
(a) total protein content of the serum; (b) relative protein fraction by
means of electrophoresis on paper using a veronal buffer of pH 8.6; (c)
concentration of low molecular weight acid mucoids in the serum by means
of Weimer and Moshin's modification of Winzler's method, and (d) nonspe-
cific serum choline sterase activity according to Zubkova and Pravdich-
Neminskaya .
Urine studies included: (a) amount of Dische -positive substances
present by means of Stumpf 'si modification of Dische's 2-desoxyribose
-'-This reaction makes it possible to determine the total content of inter-
mediate DMA -metabolism products (Footnote continued on following page.)
396
reaction} (b) DN-ase activity of the urine by Pravdina's viscosometric
method, amounts of free and bound l7-21-hydroxy-20-ketosteroids present
"by Silber and Porter's method, mucoid content by Winzler's method (after
5-day dialysis of the urine), and (c) creatine and creatinine content by
Taussky's method. In addition, clinical studies of the peripheral blood
and urine of the astronauts were made before and after flight.
1. Results of Blood Studies
The most characteristic change in the protein composition of the
blood serum of the astronauts in the training period preceding space
flight was a slight increase in the relative protein content and some
decrease in P- and 7 -globulin and mucoid levels, such as is ordinarily
observed in athletes in training and during contests, and which is con-
nected with increased physical strain and emotional tension. Some types
of astronaut training had a still greater effect on the body, as for ex-
ample in A. G. Nikolayev and P. R. Popovich on 1 June 19&2. During rest
periods, shifts in blood serum protein content and serum mucoid content
as a rule returned to normal.
Biochemical analyses of the blood of the various astronauts were
conducted at different intervals following space flight: in Yu. A.
Gagarin, from the 8th to 10th days following return to Earth; in G. S.
Titov, from the 10th to the 12th day; and in A. G. EFikolayev and P. R.
Popovich, on the day of landing and for ik days thereafter. After space
flight, the total protein content in the blood of the astronauts rose
somewhat, and some increase in the protein serum level occurred during
the first 2h hours after space flight. It is interesting to note that
an increase in the total protein concentration in the blood of Belka and
Strelka also took place in the first 6 days after flight. No essential
changes in cholinesterase activity in the blood serum were noted after
flight.
The results of clinical studies of peripheral blood showed that no
basic deviations from normal occurred in Yu. A. Gagarin either before or
after flight, while in G. S. Titov, A. G. Wikolayev, and P. R. Popovich,
leucocytosis was observed on the day of landing. Further, A. G.
Wikolayev and P. R. Popovich displayed lymphopenia and a tendency to
eosinopenia. These shifts were of short duration and were characteris-
tic of the development of a "stress" reaction in the organism.
(purine and pyrimidine compounds) (Z. Dische, 1957) , and also occurs
when the total amount of creatine, analine, and zanthine present in the
urine exceeds 1 mg per studied unit volume.
397
2. Results of Urine Studies
Clinical urinalysis of the astronauts showed that there were no de-
viations from normal during the prelaunch period. During the first 2k
hours after return from space flight, turbidity, hyaline casts (from 8
to 15 in the preparation) , and uric acid crystals were noted in the
urine of A. G. Nikolayev and P. R. Popovich. In addition, traces of pro-
tein and occasional erythrocytes and leucocytes were found in the field
in the urine of P. R. Popovich, probably due to reversible changes in
the renal filter such as are sometimes observed after physical strain or
during strong emotions .
Excretion of Dische -positive substances and enzymic activity of
acid DN-ase in the urine of the astronauts decreased during training and
after flight. During rest periods their content in the urine returned
to normal. The general trend of changes in the amount of these sub-
stances present in the urine during the prelaunch period and after flight
was opposite to that observed when the organism is subjected to the ac-
tion of ionizing radiation. Changes in the urinary excretion of Dische-
positive substances did not correspond with changes in the volume of
urine output in the majority of cases. Following return from space
flight the 24-hour urine volumes of all astronauts increased from 25 per-
cent to 75 percent.
Also observed were changes in the amounts of hormones of the adrenal
cortex, and free and glucuronic -acid-bound l7-21-hydroxy-20-ketosteroids
in the urine. Urine level of hydroxycorticosteroids increased somewhat
during pref light training periods in all astronauts, but afterwards re-
turned to normal during rest periods. The amounts of bound hydroxycorti-
costeroids in the urine before space flight varied within normal limits.
After flight, the amount of free hydroxycorticosteroids in the urine
increased sharply to 2.5-3-5 times the normal value. In Yu. A. Gagarin,
this increase was even more considerable, amounting to 10.7 times normal.
The amount of bound steroids in the urine of Gagarin, Titov, and Popovich
corresponded to the normal upper limit, while in Nikolayev it was a
little above it.
The increase of urinary steroids after space flight indicates func-
tional stimulation of the adrenal cortex and may be regarded as an adap-
tive reaction that increases the body' s resistance to the effect of
various factors connected with flight and landing. Their normalization
even in the case of a very great increase (Gagarin) shows that the effect
of the various factors being tested by the astronauts did not exceed the
physiological capacity of the adrenal glands.
During the period of preparation for space flight, mucoproteid
urine levels exceeded normal values in some cases; this is^apparently
398
attributable to fatigue. As is known, the mucoid urine level can be in-
creased by various factors, particularly heavy muscular labor. After
space flight the amounts of these substances in the urine was either nor-
mal or close to normal; later observations revealed an increase in the
urine of G. S. Titov.
Determination of creatine and creatinine in the urine was performed
only for A. G. Nikolayev and P. R. Popovich. 1 Before space flight the
creatine and creatinine urine levels remained within normal physiological
limits for both astronauts: trace quantities of creatine were observed,
and the creatinine content was from 1.0 to 1.5 g for 2U-hour urine.
During the first 2h hours after return from space flight the amount
of creatinine in the urine increased significantly in both Nikolayev and
Popovich, attaining values of 2.01 and 2.60 g for 2^4— hour urine, respec-
tively. During this period the creatine content did not change --only
traces of it were observed. Follow-up for ±h days after landing showed
normalization of creatinine content in 2U-hour urine to 1.76 g for
Nikolayev and I.36 g for Popovich.
The increased creatinine urine levels in the astronauts reflected
increased physical strain encountered in flight and during landing, and
intensification of muscular labor, both leading to increase in muscular
protein catabolism.
Thus, the totality of biochemical changes observed in the organisms
of the astronauts during preparation for space flight and after landing
indicates that changes in several metabolic processes are reversible and
quickly restored, and are characteristic of the development of a short-
term "stress" reaction in the body.
EFFECT OF ANGULAR ROTATION VELOCITIES ON THE STATE
OF SEVERAL VISUAL FUNCTIONS
A. B. Flekkel'
Speed of rotation in free fall and the consequent acceleration at
the level of the head may attain high values, which, despite their short
^De termination of the creatine and creatinine content of the urine of
A. G. Nikolayev and P. R. Popovich was performed by V. D. Blokhina and
L. P. Furayeva.
399
duration, are dangerous to human life. The literature contains limited
information on the effects of acceleration during small radius rotation,
most of which refers to animal experiments or to experiments in which
humans were subjected to rotation for "brief periods.
In studying the effect of angular rotation velocities on the state
of various physiological systems, it was essential to investigate several
visual functions: visual acuity, critical flicker fusion frequency, and
field of vision. These functions were determined before rotation, during
exposure to angular rotation at different speeds, after braking the
chair, and, in addition, on the following days. Ophthalmoscopic examina-
tions and examination of the outer coating of the eye were made "before
and after rotation. Subjects were in a sitting position and lying su-
pine: in the first position, visual functions were measured after rota-
tion around an axis in the vicinity of the pelvis; in the second position,
after rotation around axes in the vicinity of the heart, head, and feet.
Examination of the data obtained from rotation in the sitting posi-
tion reveals a definite dependence of the state of the visual functions
on the angular velocity of rotation and the degree of inclination of the
subject's trunk from the vertical axis. With increased inclination of
the subject's trunk from the vertical axis, equivalent effects on the
visual functions occurred at correspondingly smaller angular velocities.
For example, a 15 percent to 20 percent reduction in flicker fusion fre-
quency occurred at a rotation velocity of 1.75 revolutions per second
(rps) when the chair back was vertical, but at a velocity of 0.5 i*ps
when the chair was tilted 90° from the vertical. Similar changes were
noted in visual acuity and field of vision.
In evaluating the effect of the factors under study, we confined
ourselves to intensities and periods of exposure sufficient to cause a
pronounced (15 percent to 20 percent) impairment of visual function,
without establishing the limits of tolerance past which anatomical
trauma of the visual analyzer or severe visual dysfunctions would occur .
In individual cases, when the ratio of angular velocity and incli-
nation of the trunk from the vertical exceeded the values indicated
above (2 rps with the chair back vertical and 1.75 rp s with the chair
back tilted at 20° and 30°) } "the impairment of visual functions amounted
to 25 percent to 30 percent of the initial values. With the trunk in-
clined 45° and more, even when small angular rotation velocities were
used, some individuals developed hyperemia of the mucous membrane of the
lids and vessels of the eyeball, and a noticeable dilatation of the ves-
sels of the fundus.
During rotation in the supine position the dependence of the state
of the visual functions was determined by the position of the axis of
rotation with relation to the body of the subject. The effect on the
400
visual functions was considerably greater when the axis of rotation
passed through the vicinity of the head and the feet, and smaller when
it passed through the vicinity of the heart.
An impairment of visual functions imposing a 15 percent to 20 per-
cent limitation on visual efficiency occurred at 1.0 rps with the axis
of rotation passing through the vicinity of the heart, at 0.5 rps with
the axis of rotation in the vicinity of the head, and between 0.25 and
0.5 rps with the axis of rotation in the vicinity of the feet.
As a rule, changes in the visual functions were also dependent on
the duration of exposure to angular rotation. The maximum impairment of
visual functions occurred in the 5th to 6th minutes of rotation, after
which the excitability of these functions gradually was restored. Full
restoration of function was observed in the k to 5 minutes after rota-
tion.
The stabilization and restoration of the somewhat impaired visual
analyzer functions during rotation is probably the result of compensatory
reactions of the vascular system which have by that time been triggered
by simultaneous circulatory disturbances.
Analysis of the results of these studies indicates that the amount
of change in the visual functions occurring during rotation around axes
variously oriented with respect to the body depends to a considerable
degree on the magnitude of the acceleration thereby produced in the most
distant part of the body. Thus, change in the visual functions becomes
noticeable when acceleration at the head of the subject attains a value
of 0.5 to 1.0 g. A 15 percent to 20 percent impairment of these func-
tions occurs at an acceleration of 1.5 to 4.0, and a 30 percent impair-
ment at an acceleration of 2.0 to 5.5.
Severe visual dysfunctions in the form of hemorrhage into the mem-
branes of the eye, displacement of visual axes, painful sensations,
color distortion in the field of vision, or loss of consciousness, such
as are observed during radial pelvis -to -head accelerations, were not en-
countered in the course of our experiments. However, in two cases a
state bordering on swooning occurred during rotation in the supine posi-
tion about the head at a velocity of 1.0 rps.
It should be noted that the characteristics observed in changes in
visual functions during exposure to angular rotation at various speeds
were significantly similar to those of changes in the motor coordination
and other physiological functions of the subject.
J+01
REACTIVITY OF THE ORGANISM AND METHODS OF INCREASING ITS RESISTANCE
TO CERTAIN FLIGHT FACTORS
I. M. Khazen
This article sums up our experimental findings on the resistance of
animals to hypoxia, acceleration, rolling motion, explosive decompres-
sion, microwaves, and X-rays. We also studied the characteristics of
the adaptation reactions of man to hypoxia, acceleration, etc. This
enabled us to adopt a somewhat broader approach to the analysis of the
common specific and nonspecific clinicophysiological and biochemical
features noted after exposure to the aforementioned stress stimuli. We
endeavored to gain some idea of the correlations between the various
functional systems developing under the influence of a given stimulus
or set of stimuli and thereby obtain some criteria for judging the re-
activity of the organism. There is no need to show that such integra-
tive indicators are of considerable importance in programming medical
cybernetic apparatus.
Among the factors tested, we paid particular attention to oxygen
deficiency since hypoxic conditions, which we judged from tissue proc-
esses, may also occur after exposure to several other stimuli. Thus,
tissue adaptation to hypoxia is of significance in solving problems
connected with increasing resistance to acceleration, explosive de-
compression, radiation, and other flight factors.
The steady improvements being made in oxygen respiratory apparatus
and other means of supplying man with oxygen in the pressurized cabins
of airplanes not only do not exclude, but they dictate the need of
continuing the search for methods of increasing resistance to the
maximum.
In addition to the general clinicophysiological methods, we made
extensive use in all our investigations of the neuroglandular apparatus
of the digestive system as a highly sensitive indicator (I. P. Razenkov)
in studying the general homeostatic reactions to very powerful environ-
mental factors. We invariably started with the assumption that adaptation
as "a precise relationship of elements among themselves and between
themselves and the external environment" (I. P. Pavlov) is determined
not only by the response of the neuroglandular apparatus to the stimulus
directly, but also by the aftereffects. However, the aftereffects, as
a set of metabolic and structural changes, are an important indicator
of the reactivity of the individual functional systems in the integral
organism. This indicator found practical application in our early in-
vestigations that were concerned with the limits of adaptation to hypo-
xia in the established fact of "breakdown of adaptation" and its pre-
cursors (I939-I9UO) .
h02
The results of experiments on dogs and on human beings showed that
in hypoxia the gastric glands are more reactive than the other digestive
glands, thus explaining the comparatively pronounced impairment of the
processes of gastric secretion. For example, in experiments that the
author performed on himself on Mt. Elborus (highest peak in the Cau-
casus), a "breakdown of adaptation" occurred at l}-,800 m against a back-
ground of a sense of well-being and normal fitness. Besides a complete
loss of hydrochloric acid from the gastric juice with traces of blood
therein, there occurred twitching of the abdominal press muscles. These
phenomena were persistent and they continued at different altitudes
after descending from "Priyut Pastukhova" and on the plain for 3 weeks.
In a comprehensive pathogenetic analysis of these manifestations
made in the laboratory of I. P. Razenkov, Yu. M. Lazov found them to
be related to structural changes in the mucosa of the body and fundus
of the stomach. For example, keeping dogs at an altitude of 8,000 m
and exposing them for k-6 hours to a stereotypic repetition of eleva-
tions (every other day or two) resulted in increasing involvement of
the structural elements. There was almost solid necrobiosis of the
epidermis, necrosis of individual small arteries, transformation of
the chief and secondary cells into an indifferent type of epithelium,
etc. However, from about the 15th elevation on, signs of regeneration
began to set in and the process continued until complete repair (63rd
elevation) of the acute changes that developed during the preceding
actions. Under similar conditions, we failed to observe any signifi-
cant morphological changes in either the pylorus or intestine. These
facts must be regarded in a new light. They now have theoretical
significance as compensatory-reparative manifestations since they in-
dicate the presence of potential and by no means fully understood
compensatory-adaptive resources in the organism. It is reasonable
to assume that in extreme circumstances the glands of the body and
fundus of the stomach assume a regulatory role. Support for this
view comes from the similar pattern of morphological changes in the
adrenal cortex. Prolonged exposure to hypoxia is followed by degenera-
tive exhaustion of the cortex and then by complete restoration (L. A.
Langley, M. E. Sawyer, J. Stickney, and E. Van-Lear). Since the struc-
tural changes in the glands of the body and fundus of the stomach coin-
cide in time with the structural changes in the adrenal cortex and they
are in the same direction, the assumption that the function of these
organs is interlinked is justified.
The interlinking of gastric secretion and activity of the pituitary-
adrenal system was demonstrated in our laboratory in experiments on
animals and on human beings exposed to accelerations (1957-I963). In-
hibition of secretion and the duration of the aftereffects are common
characteristics in hypoxia and under these conditions. Prolonged
aftereffects were also noted in the metabolism of biogenic amines
(histamine, serotonin, epinephrine, norepinephrine, acetylcholine) both
in the blood and in some tissues. These could not but cause impairment
403
of carbohydrate, fat, protein, mineral, metabolism, etc. after sustained
and frequent exposure to accelerations. Moreover, in experiments on
rats intentionally exposed to harsh conditions (10 g for 1 minute, up to
120 actions in the course of a single month), it was found that condi-
tioned reflexes were more or less preserved despite deep structural
impairment of brain, heart, liver, kidney, and lung tissues.
After accelerations, the rate of restoration of certain impaired
functions of the gastrointestinal tract was slow and unusual in some
respects as compared with respiratory and circulatory functions . After
exposure, for example, to positive radial accelerations, changes in the
bioelectric activity of the brain and heart were restored by the third
minute, but the aftereffects lasted dozens of minutes in the salivary
glands, hours in the gastric glands, and many days in the intestinal
glands. Consequently, to predict the course of adaptation to extreme
stimuli, one must also take into account these features, i.e., all the
aftereffects in the functional systems, which throw light both on the
correlation of functions in the integral organism under the influence
of a given stimulus and on the latent effects of stresses in the ab-
scence of acute reactions.
The results of the experiments show that the various impairments
that follow accelerations, as in the case of hypoxia, are considerably
mitigated if many days intervene between repetitions of the action.
However, determination of the time intervals is closely related to the
characteristics and duration of the aftereffects.
We observed similar common characteristics in experiments on dogs
and human beings, including ourself, under the influence of "bumpiness"
in airplane flights.
The data presented above enabled us to investigate the limits of
adaptation and the potential adaptive- compensatory resources of the
organism with respect to other factors such as explosive decompression
and small doses of X-rays. The limits of adaptation are quite relative
and they can be considerably extended if the characteristics of the
stimulus and the original functional state of the organism are taken
into account. This view clearly broadens and amplifies the concept of
"adaptation energy" introduced by H. Selye in his theory of stress. It
seems to us that it is a question here of potential adaptability, the
neurohumoral mechanisms of which are controlled by the central nervous
system.
Thus, when exposed to extreme stimuli (oxygen starvation, accel-
erations, rocking movements, vibrations, etc.), the gastrointestinal
organs are incorporated in the general defense systems of the body
and the duration of the aftereffects is one of the important indications
kok
of the condition of the neurohumoral regulatory mechanisms. Extreme,
frequent stress can produce pathological impairment suggestive of
exhaustion.
This has given rise to the idea of prophylactic intervention, which
includes measures aimed at preventing the regulators from becoming in-
competent. The approach also worked in the case of exposure to X-rays,
microwaves, and explosive decompression. For example, irradiating rats
three times at 7-day intervals with a daily dose of 50 r and total dose
of 150 r (L. I. Kotlyarevskiy and coworkers) caused marked impairment
of cortical dynamics. A decrease in the conditioned reflexes was fol-
lowed by a sharp increase, with the development of phase phenomena and
disruption of active inhibition. The aftereffects persisted a long
time. Complete restoration in rats with a strong type of nervous sys-
tem required 96-I3O days.
In an investigation that we conducted jointly with N. M. Gurovskiy,
Myasnikov, and Mirolyubov, we took into account the duration of the
aftereffects and the original functional level. A second exposure to a
somewhat larger dose (60 r) was carried out 25 days later, i.e., at a
time of relatively complete restoration of conditioned activity to the
original level.' The result here was that the period of the aftereffects
lasted 15 days. A third exposure to the same dose after complete res-
toration of the conditioned reflexes resulted in even smaller changes
and the animals ' resistance to subsequent exposure to a larger dose was
increased.
The idea of using microwaves (a natural element in the environment)
as a means of increasing resistance to hypoxia occurred to us during
the comprehensive Elborus expeditions of 1939-19^0. Our aim, essen-
tially, was to influence the processes of tissue respiration and thereby
make the tissues more resistant to injurious agents. UHF electromag-
netic fields help to increase the tone of the neural regulators, en-
courage the anoxybiotic processes, activate the antihistamine enzymes
and other substances that increase resistance, stimulate epinephrine re-
actions, etc. We appraised the effectiveness of microwaves from general
clinicophysiological reactions and from the functional state of the
pancreas and intestinal glands. We observed that this physical factor
has a correcting role in hypoxia. There was a complete absence of after-
effects either at the time when the microwaves were used or during sub-
sequent experiments performed for almost k months without this factor.
Our findings on the effectiveness of microwaves are in agreement
with data recently published in the scientific press.
Physical training, as a general means of increasing resistance to
flight factors, is of major importance. In model experiments on rats
(in a comparative-physiological series, man is the most resistant), we
^05
showed that training rats just by allowing them to swim prevented them
from dying when terrestrial pressure dropped from 760 to kO mm. Ordi-
marily, 85-90 percent of the untrained animals died.
A comparison of our data with the results of experiments in which
such pharmacological agents as atropine, histamine, etc. were used re-
vealed some other characteristics of the regulatory mechanisms of the
autonomic nervous system that prevent or mitigate the impairment (mainly
very acute hemodynamic disorders of the lesser circulation- -F. I.
Pozharskiy, D. Ye. Rozenblyum, I. M. Khazen) characteristic of explosive
decompression.
It might appear that the different means that we used to increase
resistance to flight factors cause a nonspecific general adaptive re-
construction of functions. In fact, however, quite pronounced specific
reactions take place here. For example, atropine eliminated the patho-
logical reflexes from the cavity-type and other organs. Histamine
caused changes in the neuroendocrine components of regulation in addi-
tion to directly increasing pulmonary muscle tone and strengthening
resistance of the lungs to distention. Conditioned-reflex reconstruc-
tion of functions was achieved by familiarizing and simulated drops in
pressure. It is evident that the extent of resemblance is determined
by the overall effectiveness of the prophylactic intervention, although
the methods of achieving this effectiveness are completely different
and specific.
The theoretical and practical value of the characteristics of the
aftereffects noted in our experiments as general indicators of reac
tivity and lability (N. Ye. Vvedenskiy, A. A. Ukhtomskiy) is quite
obvious .
Thus, our study of the regulation of functions after exposure to
extreme stimuli shows that the better known the mechanisms of the
adaptive-compensatory processes are, the better will be the ways and
means of increasing resistance to flight factors.
To increase resistance to many flight factors on airplanes, atten-
tion should be directed to the following:
(1) Perfecting methods of general and specific physical training
with due regard for the adaptive-compensatory capabilities of the
organism;
(2) Staying in a mountain climate together with a rational diet
to effect permanent adaptation to various environmental factors acting
together;
1+06
( 3) Controlling the processes of metabolism and energy during
flight, which requires developing a rational diet during flight to pre-
serve the relative stability of the internal environment and thereby
ensure adequate physical fitness and health.
HIST0PHYSI0L0GICAL CHANGES IN ANIMALS EXPOSED TO ACCELERATIONS
I. M. Khazen, E. M. Kogan and A. S. Barer
Earlier investigations conducted in our laboratory revealed that
the higher divisions of the CNS play an integrating role in the mechan-
isms of regulation and compensation of functions following exposure to
centripetal accelerations. However, after repeated exposures the regu-
latory systems, especially the sympathetic -adrenal, become incompetent,
giving rise to a variety of clinicophysiological as well as morphologi-
cal manifestations. The latter often occur despite the externally
satisfactory general condition of the animals and the relatively good
state of preservation of the conditioned reflexes .
In one series of experiments (12 rats), we applied accelerations
of 10 g for 1 minute with an increase of 2 g per second. The experi-
ments were performed once a day at 7-day intervals for 8 weeks .
In another series (50 rats in groups of 8 and 9), the animals were
systematically exposed to accelerations of 10 g per minute k times a
day at 30-minute intervals.
In a third series, 12 rats were exposed to 5 g in 20 minutes, the
other conditions being the same as in the first series.
The animals were decapitated as soon as the centrifuge was stopped.
Tissues were obtained from the brain, heart, lungs, liver, and kidneys
for histological investigation. The specimens were stained with
hematoxylin-eosin and by Nissl's method.
Results
The specimens from the organs of the first series of rats revealed
vague signs of stasis only in a few cases.
The specimens from the second series of rats exposed h times to
accelerations (10 g-1 minute at 30-minute intervals) exhibited marked
koj
changes in various organs and tissues. For example, the cerebral ves-
sels were dilated and overflowing with "blood, with slight perivascular
and intercellular edema. The heart muscles were somewhat loose and .
edematous . The myocardial capillaries were dilated and congested, with
polarization of the formed elements and plasma. Some hyperemia was noted
in the blood vessels of the lungs. The liver was characterized by inter-
cellular edema with plasmorrhagia . In the central veins- -stasis. The
Kupffer cells were edematous, their nuclei rich in chromatin. In the
kidneys--some hyperemia. The epithelium of the gastric mucosa was hy-
peremic. Except for signs of stasis, no changes were noted in the wall
of the small intestine. The adrenal cortex was lacking in lipids.
On the second day of the experiment, i.e., after 8 exposures to
the accelerations, stasis was particularly pronounced in the arterial and
venous vessels, with separation of the plasma from the formed elements
of the blood. In most of the cerebral capillaries, the nuclei of the
endothelium were swollen and edematous, some of them being in the lumen
of the blood vessels. The muscular layer of the wall of the cerebral
arteries was also changed. For example, the nuclei of the muscle cells
were twisted like a spiral and crowded to the periphery, resulting in
the formation of nonnucleated areas. Characteristic changes were also
noted in the liver. The structure of a large part of the lung tissue
was preserved but filled with a hemorrhagic exudate.
More pronounced changes were observed in the animals after 16 ex-
posures, i.e., on the lrth day. The external layers of the cortex and
capillaries of the brain were edematous. The walls of some of these
capillaries showed degenerative changes and their lumens were filled
with leucocytes. There were also major changes in the myocardium.
The intermuscular capillaries were filled with blood and dilated.
Areas of muscular tissue could be seen with pronounced intermuscular
edema and weakly staining nonnucleated cells. There were also signifi-
cant changes in the lungs, the tissue of which was saturated with a
hemorrhagic effusion that filled the alveoli and many of the small
bronchi. The pulmonary blood vessels were markedly changed. Individual
portions of the muscular layer were missing, while the surviving nuclei
of the muscle cells had moved to the periphery where they collected in
compact masses resembling a palisade. The adventitia of the blood
vessels formed a scalloped border and their walls were saturated with a
protein effusion. Vicarious emphysema was noted in some portions of
lung tissue. Some portions of the kidneys revealed destruction of the
nephrons and proliferation of connective tissue therein.
The greater the number of exposures, the more pronounced was the
proliferation of connective tissue. For example, after 2h exposures,
i.e., on the 6th day of the experiment, the lung tissues had thickened
interalveolar septa as a result of proliferation of connective tissue.
Besides stasis, there were many leucocytes in the blood vessels.
II iiiiiiiinimiiniiiBiiiii
1*08
The signs of degeneration also embraced individual bronchi, where
the epithelial and muscular layers were particularly affected. The
degenerative changes in the myocardium noted above were more widespread
at this time and there were portions of muscular tissue with nonnucleated
cells. The marked proliferation of connective tissue covered some of
the renal glomeruli almost completely.
The proliferation of connective tissue intensified during the sub-
sequent stages of the experiment. After 32 exposures, i.e., on the 8th
day, the interalveolar septa of the lungs were thicker. There was also
marked thickening of the muscular layer of the arteries in different
organs. As before, the signs of stasis with polarization of the formed
elements and plasma were pronounced. The liver was characterized by edema
of the interlobular bile ducts, while the brain was the site of conges-
tion and dilatation of the vascular bed. Another noteworthy fact was
that the nuclei of the main mass of cortical cells had two or more
nuclei each. This was particularly noticeable in the external layers
of the cerebral cortex.
In the animals exposed 120 times, i.e., on the 30th day of the
experiment, the changes were even more pronounced. Of particular inter-
est were the morphological changes in brain tissue, especially the signs
of degeneration with vacuolar degeneration of a great many nerve cells.
There were other nerve cells, similar to those described by some histol-
ogists as nerve cells, which were in various stages of amitotic division.
Specimens from rats of the third series (accelerations of 5 g - 20
minutes) revealed marked hyperemia, perivascular and interstitial edema
of brain tissue, edema and fraying of the myocardium, hemorrhagic ef-
fusions in some pulmonary alveoli, and signs of degeneration of lung
epithelium.
Thus, analysis of the factual material shows that there is a pat-
tern of increase in the morphological changes in various tissues and
lungs of animals in relation to the frequency of exposure. For ex-
ample, after frequent daily exposures, the morphological changes noted
during the first days of the experiment were acute in nature (hemor-
rhages, rupture of the vascular walls, stasis, etc.), but later the
proliferation of connective tissue and deep degeneration of different
cell structures became predominant.
By way of contrast, in the first series of experiments (7-day
intervals between experiments), even 8 exposures (10 g - 1 minute) did
not result in noticeable morphological changes. Signs of cumulation
were not found in these experiments .
409
A definite relationship was noted between the morphological changes
and duration of action after 8 exposures to accelerations of lesser in-
tensity but greater duration (5 g - 20 minutes) at equal time intervals
over 7 days. The ensuing morphological changes were distinct. In all
the variations of the experiments, the reaction of the cardiovascular
system was most pronounced. One of the first and most characteristic
manifestations of accelerations is impaired permeability of the vascu-
lar wall. This was also shown by the passage of formed elements per
diapedesin/ a feature of acute hypoxia.
The morphological data presented in this report have been confirmed
by V. G. Petrukhin, Ye. F. Kotovskiy, and others. They occur regularly
and show that the changes in the tissues investigated are related not
only to the intensity, direction, duration, frequency, and intervals
between exposure, but to the functional state of the organism.
SOME RESULTS OF MANNED SPACE FLIGHT AND PROBLEMS IN SPACE
BIOLOGY AND MEDICINE
V. I. Yazdovskiy
(Text of the report not included.)
1+10
THE EFFECT OF ADEQUATE STIMULATIONS OF THE VESTIBULAR APPARATUS
ON THE ELECTRICAL POTENTIAL OF THE STOMACH
V. T. Khlebas and N. P. Kozhukhar'
A number of recent reports written for the most part by native
Soviet authors (N. M. Sisakyan, V. V. Parin, V. N. Chernigovskiy, V. I.
Yazdovskiy (1962) , V. I. Yazdovskiy, M. Yemel'yanov, N. Gurovskiy (1962),
0. G. Gazenko, A. M. Genin, Ye. M. Yuganov (1961) and others) have shown
that a stay by man in a prolonged state of weightlessness is accompanied
in individual cases by vegetative disturbances.
They assume that prolonged weightlessness can lead to the develop-
ment of motion sickness which arises as a result of an increase in excit-
ability of the receptors of the semicircular canals of the vestibular
apparatus and accumulation of the effect of Coriolis acceleration.
Study of the mechanism of vestibulo -vegetative disturbances , the
establishment of the causes of their occurrence, and an explanation of
the possibilities of an increase in man's working capacity in space is
of great importance.
Significant disturbances of vegetative functions were observed by
many scientists in experiments on animals after a 10-12 minute sickness-
inducing motion. Significant reflex disturbance of the functional activ-
ity of the organs of digestion were found in this complex of vegetative
shifts .
The present work has attempted to explain the effect of strong ade-
quate stimulations of the vestibular apparatus upon the secretory-motoric
potential of the stomach which is one of the most important indexes of
its functional condition. Reports by V. I. Venchikov (195*)-), Ye. F.
Bogovarova (19I+5), Resnikova (1961) and others, established that a defi-
nite relationship exists between the secretory-motoric functions and the
potential of the stomach. The more the secretion of the glands, the
lower the biopotential of the stomach; the stronger the contractions,
the greater the amplitude of oscillation of the potential.
Research Method
The investigations were carried out in chronic experiments on dogs
with a stomach fistula (Basova) on an empty stomach. 1o obtain adequate
stimulation we employed a rotating circular table with an electric drive
(V. T. Khlebas, N. P. Kozhukhar, I. F. Sokolyanckiy (1963)) and a Zhilov-
type swing adapted for work with animals . The number of revolutions of
the table was 30 per minute; the frequency of rockings was 60 per minute;
Uli
the amplitude of the rocking was 90°; the length of the bar was 3 • di-
meters .
The biopotential of the stomach was led off by clay non-polarizing
electrodes, one of which was inserted into the stomach through the fis-
tula; the other was attached to the skin of the back between the thisd
and fourth lumbar vertebrae. The signal went to a direct current ampli-
fier and to the registering system (N. P. Kozhukhar, I. Ya. Serdyuchenko
— unpublished work) .
Before beginning the recording of the potential, the stomach was
washed out with warm water (3^~ 36°C), the electrode was inserted and the
animals were maintained for the course of an hour in a condition of rest.
After this the control recording of the initial potential was made, the
stimulus was then engaged and the registration of all subsequent changes
was continued during the action of the stimulus and after switching it
off.
The animal was placed on the stand of the rotating table, its head
was fastened in a natural position and it was located kO -50 cm from the
center. In the swing the animal's extremities were also fastened down.
Results Obtained and Their Discussion
We studied the effect of adequate stimulations on the character of
changes in bioelectric potential in three dogs in chronic experiments.
Prolonged rotation (from 10 to 60 minutes) caused in the overwhelming
majority of experiments a lowering of the bioelectric potential of the
stomach of 8-2*1- mv, which amounted to 6-50 percent of the initial value
which was within the limits i+O-^S mv.
It must be pointed out that stimulation of the vestibular apparatus
by rotation in our experiments caused a lowering of the potential of the
stomach of approximately the same magnitude as feeding of the animals
with fat and irritation of the vagus nerve with an electric current in
the experiments of other authors (A. I. Venchikov (195*0 j Ye. F. Bogo-
varova (19V?))- The initial potential in the reports of these authors
was equal on the average to k& mv.
As a rule lowering of the potential set in during the stimulation,
8-20 minutes after its initiation; before this point an insignificant
rise of potential was observed. The potential stayed at the lower level
after which a slow rise (recovery) set in over a period of 30-to minutes,
sometimes significantly longer, and in individual cases the potential did
not return at all to the initial value, for a period of one hour after
cessation of the rotation.
1*12
In nearly all experiments with the dog "Chernushka" , in addition to
the changes in the potential, the typical symptom complex of seasickness
was achieved, which was manifested by increased salivation, urination,
vomiting and defecation, while only salivation was observed with the dog
"Ryzhik" .
In the dog "Chernushka", the time of action of the stimulation neces-
sary to obtain maximal lowering of the potential was steadily shortened
(from 35 to 13 minutes) .
Changes in the potential of the stomach of some other character
were obtained in the third dog "Zhuk" . In all experiments with her,
with the exception of one, an increase of potential of 5-10 millivolts
was obtained instead of the decrease observed in the other dogs. With
this dog, not once was vomiting seen; the rise of potential in her set
in gradually in the 30 -kO minute period after beginning the rotation,
while the initial magnitude of the potential did not differ from the
usual value.
An analysis of the results obtained allow the conclusion that the
fall in potential is the result of an excitation of the gastric glands
under the influence of strong rotational stimulations of the vestibular
apparatus .
Depending on their strength, these processes approach and sometimes
exceed the reflex stimulation of the digestive glands during feeding.
After cessation of the stimulation of the vestibular apparatus the poten-
tial of the stomach was restored faster than in the process of digestion.
All of this testifies to the protective character of these reactions.
Strong stimulations of the vestibular apparatus by rotation leads
to significant shifts in the secretory function of the stomach which are
reflected in changes in the bioelectric potential.
We obtained a series of electrograms which recorded the changes in
the potential of the stomach reflecting the hunger period, and, in addi-
tion, the rhythmic contractions of the stomach muscles beyond that
period; the frequency of these contractions was 0.5-1 per minute with
the average amplitude 5-6 mv. Vomiting was reflected in the EGG in the
form of individual rapid oscillations of the potential of large ampli-
tude (10-15 mv). *
We carried out a second series of experiments which was essentially
a study of the effect of motion-induced sickness on the biopotential of
the stomach.
Results of these experiments showed that motion-induced sickness
appears to be a stronger force than rotation as a stimulator of the
ill 3
secretory-motoric function of the stomach which is manifested in a sig-
nificantly greater lowering of its electric potential during a shorter
time of action. Thus, with motion-induced sickness, the potential of
the stomach is lowered "by 11-30 mv while with rotation it is lowered 8-
12 mv.
Especial attention is warranted "by the results obtained in experi-
ments on the dog "Zhuk" . Whereas rotation led to an increase of poten-
tial of 5-10 mv, motion-induced sickness, on the other hand, caused an
8-15 rov lowering of it. The time of action of the stimulation to achieve
the effect was, in the dog "Chernushka" 3-12 minutes, in "Ryzhik" 11-13
minutes, and in the dog "Zhuk" 17-18 minutes which testifies to the
greater resistance of the organism of this animal to strong, unusual
vestibular influences.
Characteristic of the initial potential of the stomach with the
mot ion -induced sickness was its tendency to rise depending on the in-
crease in the number of experiments carried out. Thus, for example, in
the dog "Chernushka" it rose from i+5 mv in the first experiment to 75 mv
in subsequent tests: in the dog "Zhuk" it rose correspondingly from 55
to 63.
It must be assumed that in the course of training (setting up of the
experiments) the dogs develop defensive reactions to strong stimulations
which cause the unsuitable reactions of the secretory-motoric apparatus ■
of the stomach .
Conclusions
1. Strong and prolonged adequate stimulations of the vestibular
apparatus cause changes in the bioelectric potential of the stomach which
are reflected as a rule in a lowering of the potential.
2. Results obtained support the position that lowering of the po-
tential of the stomach coincides with excitation of the gastric glands.
3. Motion~induced sickness is stronger than rotation as a stimula-
tor of the gastric glands.
k. Secretory-motoric reactions of the stomach to stimulations of
the vestibular apparatus of different animals are not identical in inten-
sity.
5. Electrogastrography may be used as a method to study the diges-
tive functions of animals under conditions of cosmic flight.
uik
THE STATUS OF ANTIC OAGUIATING MECHANISMS UNDER CONDITIONS
OF PROLONGED HYPOKINESES
Ye. I. Chazov and V. G. Ananchenko
We have not found reports in native Soviet or foreign literature
which concern the study of anticoagulating mechanisms under conditions
of prolonged hypokinesic states. At the same time this problem has un-
doubted interest since some changes characteristic of prolonged hypo-
kinesis (disturbance of vascular permeability, disorders in blood cir-
culation) can undoubtedly increase the tendency to thrombus formation.
It was suggested that we study the status of the thrombus -forming prop-
erties of the blood in 12 volunteers under hypokinesic conditions. To
judge the anticoagulation capacities of the organism we studied the con-
tent of free heparin in the blood by the Piptei method, the fibrinolytic
activity of the blood by the Bidwell method, the plasma heparin tolerance
by Hormsen's method, and thromboelastography by Hartert's method (using
the "Hellige" thromboelastograph) . Three series of investigations were
carried out on practically healthy subjects aged 19 to 20.
In the first group studies were carried out of all the above listed
indexes in k subjects before and after a 3 -day period under hypokinesic
conditions. In 3 of them we were not able to find any regularity at all
in changes of state of the thrombus -forming properties of the blood.
Thus, blood heparin before and after the investigation fluctuated
within the same levels of 5-6 units/ml; the plasma heparin tolerance
( 15-17 minutes), the level of blood fibrinogen (250-300 mg percent) and
the fibrinolytic activity (25-30 percent) were normal before and after
hypokinesis. In only one subject of this group was a rise noted in the
content of blood heparin (to 10 units/ml) , an increase in the plasma hep-
arin tolerance (to 22 minutes), an increase in the fibrinolytic activity
of the blood (to 62 percent) . These changes were established on the
thromboelastogram. It must be noted that after the tests on the centri-
fuge, following immediately after a 3-day" period in bed, in only one case
of the four, was the appearance noticed of small hemorrhages into the
subcutaneous cellular tissue.
More regular changes were obtained in the second series of investi-
gations with prolonged hypokinesic states, when k subjects were in a
state of absolute rest for a period of 20 days. It was found that pro-
longed hypokinesis in healthy persons leads to an increase in the anti-
coagulating and lytic properties of the blood, which leads to lessening
the possibilities for thrombus formation. Most expressed was the in-
crease in the fibrinolytic activity of the blood, which in 3 cases reached
100 percent and in one case only, rose from 3^- percent to 50 percent. In
this subject, changes were not observed in the content of blood heparin,
it-15
while in the 3 others its content rose 2 units/ml. Changes were marked
in the plasma heparin tolerance, reflecting in a significant degree the
possibilities of thrombus formation. In 3 cases the plasma heparin tol-
erance rose from 15-17 minutes to 22-26 minutes and only in the very same
case of Subject M, where there were no changes with respect to blood hep-
arin and the fibrinolytic activity was insignificantly lowered, the
plasma heparin tolerance not only did not rise but it was even lowered a
little (from 17 to 12 minutes) .
In all k subjects, at the end of the period of hyperkinesis, the
values for blood fibrinogen were lower (100-250 mg percent). The charac-
ter of the thromboelastograms supported the data of the biochemical stud-
ies. Thus the results of the investigations were found to be directly
opposite to those assumptions which were mentioned in connection with
the possibilities for thrombus formation in hypokineses. How is this
explained? Most probably, the increases observed in the anticoagulating
and lytic properties of the blood are associated with the functions of
the defensive anticoagulating systems of the organism, responding in a
similar way to the appearance during hypokinesis of conditions, which in-
crease the tendency to thrombus formation. This does not exclude the
situation that the changes observed take on the character of 'a "stress",
associated with the stay of a healthy man under conditions which are un-
usual for him.
The changes observed in the character of the thrombus -forming prop-
erties of the blood must be studied during prolonged hypokineses, as a
factor conducive to the occurrence of petechias, hemorrhages, the appear-
ance of which has already been noticed particularly by Dietrich and co-
workers .
In this connection undoubted interest is suggested by the data ob-
served in the third series of studies. This group of k subjects also
remained in a prolonged bed regimen, but systematically carried out a
complex of definite physical exercises. It was found that in this group
of healthy people no increase was noticed in the fibrinolytic activity
of the blood and in the content of free heparin. Probably, carrying out
the complex of physical exercises in the period of hypokinesis can be a
factor which prevents the occurrence of similar reactions to a rise in
the anticoagulating and lytic properties of the blood.
W.6
TEE EFFICACY OF TEE PHARMACOLOGICAL PREPARATION Nil IN COMBATING
MOTION SICKNESS OF AIR TRANSPORT PASSENGERS
A. V. Chapek
Among the many thousands of passengers of various ages and states
of health who daily employ modern air transportation, people are encoun-
tered who suffer in flight from airsickness of different etiologies.
According to our findings over many years of study, 12-13 percent
of the people are subject to motion sickness in flight on piston-driven
airplanes, and 2.5-3 percent in flight on planes with gas turbine en-
gines.
For prophylaxis of passenger airsickness and to furnish comfortable
flight conditions, the problem of developing reliable agents to combat
motion sickness, including therapeutic agents, is a very current task.
It is known that for prophylaxis and therapy of motion sickness on
various kinds of transport (sea and other types) many pharmacological
agents have been suggested. However, the therapeutic agents used in
practice do not always give a positive effect especially against the mo-
tion sickness of flight passengers.
Starting from modern concepts of the pathogenesis of motion sick-
ness (V. I. Voyachek and others) in transport including flight transport,
and, also, influenced by the extra -labyrinth and emotional causes of mo-
tion sickness in flight, we tested the efficacy of a new therapeutic sub-
stance — Nil tablets (prepared by the S. Ordzhonikidze Chemico-
Pharmacological Institute, Ministry of Health, USSR) for motion sickness
of passengers in flight.
The therapeutic preparation Nil, which contains camphorated scopola-
mine, hyoscyamine and nicotinic acid, exhibits a stimulating action on
the central nervous system and lowers the excitability of its parasympa-
thetic section. The nicotinic acid which is part of the tablet has a
positive action on disorders of the internal organs (heart, liver) and
on ulcers. It exhibits a vasodilating action (M. D. Mashkovskiy) . Side
effects of the tablet are dryness in the mouth and reddened countenance.
After ingestion these effects go away automatically.
The efficacy of the therapeutic agent, the tablet Nil, was confirmed
under laboratory conditions with experimental motion sickness and in
flight. In flight we carried out two series of experiments; in one
series of tests, passengers who were subject to motion sickness were
given Nil tablets, in the other, aeron,l as a control. The Nil tablets
and aeron were given for prophylaxis and therapy of motion sickness.
iTr. note: Aeron consists of camphorated scopolamine and camphorated
hyoscyamine.
hll
Both series of tests were carried out on flight journeys at an ele-
vation of 2000-3000 meters on piston airplanes on the Far East and other
routes (Moscow-Irkutsk-Khabarovsk-Moscow and others) .
Individual flights lasted an average of 2.5 to 30 hours with stops.
The total number of hours in flight in the first series of experiments
was klO hours, in the second, 51^ hours. Under observation in the first
series of experiments were h6o people, and in the second, 560 people, in
all 1020, aged 5 to 70; of these 136 were exposed to motion sickness, 68
in each series of experiments.
An experiment under laboratory conditions checked the resistance to
experimental rocking (on a four bar K. L. Khilov swing) and to V. I.
Voyachek's OP test using subjects who were suffering disturbance of the
vestibular -vegetative apparatus to an average and severe degree without
administration of Nil tablets and after their use.
The following was used as a criterion for evaluation of the positive
action of the pharmacological agents, Nil and aeron tablets: the absence
or cessation of vestibular -vegetative symptoms of motion sickness in pas-
sengers (turning pale, sweating, weakness, nausea), good or satisfactory
subjective feeling in passengers and in test subjects who had disturb-
ances of the vestibular apparatus at the time and after movement on the
four bar swings with use of the therapeutic agents.
Experiments under conditions on the ground in people with disturbed
vestibular-vegetative apparatus on the rotating chair (0P T ., TT ) and
on the four bar swings without the use of the therapeutic agents and
after ingestion of the Nil tablets showed the following: In those people
suffering to an average and severe degree from disturbances of their
vestibular-vegetative apparatus, of various etiologies, the test on the
rotating chair (OP) and on the four bar swing was accompanied by perspi-
ration, nausea and vomiting in 2-5 minutes of rocking; when the test was
repeated, after ingestion of Nil tablets, these same people (with a dis-
turbed vestibular-vegetative apparatus) withstood well the 0P T , 15-minute
rocking, and OP and symptoms of motion sickness were not noted in them.
Experiments with experimental motion sickness on the four bar swings
conclusively showed that use of the Nil tablets curbed well the manifes-
tation of symptoms of motion sickness in people suffering from disturb-
ances of the vestibular-vegetative apparatus to an average or severe
degree .
Results of tests in flight, using Nil and aeron tablets for passen-
ger motion sickness showed the following: (a) Nil tablets showed better
and excellent effects in 31 passengers, and a satisfactory effect in 25
1kl8
people out of 68 (82 percent); (b) aeron showed a better effect in only
15 people, and a satisfactory effect in 12 people (less than 18 percent),
and (c) aeron — in 25 people (26 percent).
According to reports by passengers and observations by a physician
and plane flight personnel, the Nil tablets helped well and excellently
against motion sickness and improved the general condition-of -passengers
suffering the effects of rocking in flight. After ingestion of Nil tab-
lets the passengers did not experience nausea and other unpleasant symp-
toms of motion sickness. The Nil tablets did not cause side effects.
In those cases where aeron did not show a satisfactory effect
against motion sickness, Nil tablets did give a positive effect. Passen-
gers — who suffer from motion sickness to a serious degree, in whom vom-
iting usually appeared right after takeoff or in 15-20 minutes of flight- -
after ingestion of Nil tablets 30 minutes before flight, withstood well
the prolonged flight, the associated acceleration during flight, the
landing and bumping.
Our investigations, carried out under laboratory conditions on the
four bar swing and directly on prolonged flight journeys which involved
weak, moderate and strong bumping, permit the following conclusions:
1. In people suffering from disturbances of the vestibular -
vegetative apparatus to an average or severe degree, prophylactic inges-
tion of Nil tablets has a positive effect — rocking is borne well without
manifestation of symptoms of motion sickness, at the time and after a
15 -minute rocking on the four -bar swing; under flight conditions the Nil
tablets showed excellent, good and satisfactory efficacy in 82 percent
of the cases of passenger motion sickness; aeron gave good and satisfac-
tory efficacy in Ik percent of the cases.
2. In degree and quality of efficacy, Nil tablets surpass aeron
and other therapeutic agents known to us (medinal, difazin and others)
suggested for motion sickness on a transport.
3. The pharmacological preparation --Nil tablets directed for pro-
phylaxis and therapy of air diseases, can be recommended for use among
passengers of air transport, subjected to motion sickness.
Nil tablets, as a therapeutic agent for motion sickness on air
transports, have been approved by the Pharmacological Committee of the
Ministry of Health, USSR.
It must be noted in conclusion that, in addition to the use of
effective therapeutic agents against motion sickness in flight passen-
gers, it is necessary to have comfortable hygienic conditions in the
passenger cabins of the planes in the form of the microclimate, lowering
U9
of the intensity of the general level of noise, vibration and adherence
to the parameters of vertical speed of descent of the planes during turn-
ing for a landing.
THE INFLUENCE OF AGE -ASSOCIATED CHANGES IN OLDER PILOTS
DURING RE -LEARNING IN THE NEW AVIATION TECHNOLOGY
AND DURING PERFORMANCE
A. V. Chapek, V. P. Yerokhin and I. P. Poleshchuk
Study of the influence of age -associated changes on pilots during
re -learning in gas turbine planes is of definite theoretical and practi-
cal interest and is directed toward assuring the safety of the pilots.
In the native Soviet and foreign literature available to us, we
were unable to find special reports devoted to the study of the influence
of age-related changes on pilots older than kO years during piloting of
modern gas turbine planes. As far as we know, no one has studied this
problem.
The aviation agencies (Sabena, SAS, KLM and others) of capitalist
countries recommend establishing the age limit of 43-55 for persons as-
signed to re -learning piloting in gas turbine planes. It is not possible
from the available literature sources to establish the criteria on the
basis of which the agencies in foreign countries establish the indicated
age limit.
The methodology in the present report provided for studies of physi-
ological functions and the quality of flying progress and of flying work
by pilot -students and pilot -instructors aged ^0-50, and aged 30-39> as a
control procedure.
Pilots were studied under conditions on the ground and in flight
for the following: higher nervous activity, memory, shifting of atten-
tion, visual sequential form, cerebral biopotentials, arterial pressure,
and the quality of the development of skill in experimental estimation
of short intervals of time.
Evaluation of flying progress and of the quality of piloting by the
pilot -students was carried out by instructors who used a five -point sys-
tem. This practice -proven method of evaluation of the quality of pilot-
ing, is most credible and this has been shown by many years of observation
by instructor personnel.
1+20
The results of the physiological studies were as follows:
1. The correlation of the "basic nervous processes in pilot students
is on the same level, in all age groups, the number of disturbances of
the differentiators does not increase with age; there is no foundation
for considering that older pilots (1(0-50 years) have age-associated dis-
turbances in their basic nervous processes.
2. The average magnitudes of numbers kept in mind, which is charac-
teristic of the visual memory in pilots of the older group and of the
control group, are approximately equal; consequently, it is wrong to
speak of impaired memory in older pilots.
3. The length (duration) of performance of the test on shift of
attention in pilots of the older age groups takes more time than in
pilots of the control group; however, the quality of the shifting of at-
tention in pilots of the older group is better than in the pilot -students
of the control group.
k. The average magnitudes of duration of the visual sequential form
and its latent period do not indicate a decrease in the function of the
cortical section of the visual analyzer in older pilots.
5. The formation of conditioned-reflex contact communications, in-
directly characteristic of the quality of the development of skill, takes
place in a completely successful manner in older pilots and with the same
regularity as in pilots of the control group (30-39 years).
6. The time of execution of simple sensory -motoric reactions in
all pilot -students is approximately the same; the speed of a simple re-
action is not impaired with age.
7. The restoration of functions of higher nervous activity (to the
initial condition) after extended flights by older pilots proceeds more
slowly than in pilots of the control group; here, evidently, is a mani-
festation of the influence of the changes on the process of restoration
of the functions of the organism after pronounced fatigue — of a 10 -hour
flight .
In all pilots, independently of age, the cerebral biopotentials
(L. V. Sadovnikova) after prolonged flight preserved their clarity,
regularity and expression of a- activity in the regions of the brain;
after prolonged flights, the intensification of the process of inhibi-
tion was more pronounced in older pilots than in pilots of the control
group .
The average magnitudes of the pulse and arterial pressure in pilot-
students and instructors of different ages did not give any actual
421
deviation at all from the accepted norm in the clinic and in physiologi-
cal states; however, in individual pilots from 40-50 years of age, a
lowering occurred in the acuity of vision to 0.7-0.8 and of hearing to
1.5-1 m on reception of whispered speech. Lowering of the acuity of
vision and hearing in the older pilots examined, according to the state-
ment of the instruction personnel, does not show a negative influence on
flying work, progress and quality of piloting.
According to the results of a questionnaire the overwhelming major-
ity of older pilot-students do not notice in themselves increased weari-
ness after educational, duty and journey flights. They also do not show
absentmindedness, forgetfulness or ineffective operation in flight, which
could be associated with the influence of age-related changes.
Accumulation of skill in older pilots, judging by the formation of
conditioned-reflex contact communications, both under experimental condi-
tions and in the process of re-learning, of piloting gas-turbine planes,
proceeds as successfully as in the control group pilots.
Flying progress and the quality of piloting by pilot-students of
the older age groups and control groups was evaluated by the instructors
on the five-point system as "good" and "excellent".
Generalization of the experimental material permits the conclusion
that the tests do not succeed in finding a difference on the psycho-
physiological plane between pilot -students of the older age groups (40-
50) and of the control group, which could be negatively manifested in
the progress of the process of re-learning piloting in gas-turbine air-
planes. In a number of cases, representatives of the mature age (45-49)
have some pre-eminence. This can be partly explained in that the group
of older pilots is made up of more capable pilots, who have remained in
the ranks of aviation as a result of special and natural selection.
Age -associated changes (decrease in acuity of vision and hearing)
in older pilots, judging by the results of an experimental study and an
evaluation of flying progress do not show a negative influence on pilots
possessing skills of piloting in planes with gas -turbine engines.
The materials of the experimental study under laboratory conditions
and in flight in the process of flying training, and also the observa-
tions by the instruction personnel, permit the conclusion that an age
limit for pilots, assigned to re -learning piloting in gas -turbine en-
gines, is apparently 45 years of age. Further studies will be needed to
make this limit more precise.
U22
SOME MICROORGANISMS AS INDICATORS OF SOLAR ACTIVITY"
AND PRECURSORS OF SOLAR FLARES
A. L. Chizhevskiy
A concrete solution of the problem of the effect of solar emissions
on living things is difficult to find owing to our inadequate knowledge.
However, the mass of available statistical data and some microbiological
experiments are now bringing the solution closer. The most important
consequence will be our ability to forecast astrophysical phenomena
(e.g., flares) accurately several days (k- 6) in advance. Observations
of this kind will then have enormous practical significance both for
space science and for clinical medicine.
Our investigations, which date back to 1915, showed that nerve
cells and certain microorganisms are highly sensitive to solar activity,
to the passage through the central meridian of the sun of spots, pro-
tuberances, flocculis, and very intense flares, emissions of solar mat-
ter. A "ruggedization" of the spectrum takes place during a flare. The
heavy streams of hard X-rays and high-energy corpuscles in the space
around the sun are extremely dangerous to unprotected man.
After studying in detail the daily or 10 -day dynamics of epidemics,
not only were we able to calculate the closeness of the relationship be-
tween epidemics and cyclic activity of the sun, but in some instances
found that sharp peaks in the epidemics forecast astrophysical phenomena.
This "early warning" was quite accurate in the case of mortality from in-
fectious and cardiovascular diseases (myocardial infarct, insults, sudden
death) . However, the maximum of epidemic development (annual figures)
sometimes occurs a year after a maximum of cyclic activity, forming a
correlation coefficient of 0.8-0. 9; with insignificant errors (i0.009 to
±0.02). I have studied the pattern of plague, cholera, influenza, diph-
theria, scarlet fever, dysentery, and other epidemics over a long period
of time and in many countries. I studied the relationship between most
plagues of the 19th and 20th centuries and solar activity and noted some
important details that had previously escaped the attention of epidemi-
ologists. The results of my studies, published in 192U-1930, were edited,
in part, by Prof. N. A. Semashko who considered them highly significant.
A portion of my monograph (pages 1-2^+0 ) on the subject was published in
1938 by the Paris Academy of Medicine. Entitled Les Epidemies et les
Perturbation Electromagnetiques du Milieu Exterieur, the work was edited
by a member of the Academy, Prof. Leniel -Lavas tine.
Since no one knew which is most dangerous to man outside the earth's
atmosphere — electromagnetic radiation of excited places on the sun, or
emission of high-energy particles during major flares, or perhaps the
two together (Z-radiation) — it became necessary at the end of the 1920s
423
to find an extremely sensitive biological reaction capable of forecast-
ing possible early (within a few days) emissions of solar matter in the
atmosphere that are unpleasant or even dangerous to man. Konstantin
Eduardovich Tsiolkovskiy had some conversations with me on the subject.
It is reasonable to assume (and he emphasized the word "assume")
that some "perturbed" places originate in the interior of the sun rather
than on the surface and that emissions emanate therefrom to which cer-
tain sensitive nerve cells or microorganisms respond. The theory of ex-
cited places originating deep in the sun has been elaborated by hello -
physicists in the Soviet Union and abroad (Hoyle, Bjorknes, Alven, Valen,
and others) .
"To direct a stellar spacecraft in another orbit and enable it to
avoid entering a flux of dangerous solar radiation, we must know several
days in advance the time that this dangerous radiation will occur,"
Konstantin Eduardovich told me. The daily or 10 -day curves of epidemic
outbreaks, whose peaks clearly anticipated the instrumental recording of
solar activity, encouraged him greatly. After studying these curves, he
asked me to try to produce .a similar effect in the laboratory. I started
to work on the problem in 1929. Several years passed, however, before
the main outlines of the experiments became more or less clear. It was
necessary to study hundreds of different strains of bacteria with differ-
ent methods of cultivation, nutrient media, and incubator temperatures.
Our persistence was justified, for we found suitable microorganisms and
developed a method of tracing their reactions to perturbations of matter
inside the sun, thus making forecasts possible.
We were joined by the Kazan bacteriologist and diphtheria special-
ist S. T. Vel'khover who had been influenced by our earlier investiga-
tions of diphtheria epidemics (192U-1930) in a number of countries. In
a joint work carried out shortly before World War II, we obtained in bac-
teria a "lead effect" that preceded the astrophysical instrumental data
by U to 5 days, i.e., when no distinct changes could as yet be detected
in the surface layers of the sun. Together with our earlier statistical
curves and results of numerous experiments, it was a positive achievement.
The mean of 19 superpositions along the "0" axis ("day of ejection") was
highly significant.
It seems that peculiar inclusions in certain microorganisms are a
very sensitive detector of the aforementioned radiations. By a change
in their delicate properties at the atomic -molecular level, they signal
powerful nuclear processes taking place inside the sun.
The foregoing suggests that we now have available methods of pre-
dicting the solar emissions that are most dangerous both to human beings
outside the earth's atmosphere (astronauts) and to sick persons on earth.
h2k
SIGNIFICANCE OF PARASYMPATHETIC NERVOUS SYSTEM TONE
IN INCREASING RESISTANCE TO FLIGHT FACTORS
M. D. Chirkin
This report presents the results of the author's investigations,
carried out at different times, on the interaction of the body and un-
usual environmental factors and a comparison of the data with the liter-
ature. The author was concerned with the physiological mechanisms that
increase human tolerance of flight factors (low "barometric pressure,
oxygen deficiency, accelerations, altitude meteorism, etc.). One of the
most important of these mechanisms is change in the tone of the parasym-
pathetic nervous system, chiefly that of the vagus nerve center, which
is constantly regulated "by the cerebral cortex. We shall try to support
our view with factual data obtained from our investigations and observa-
tions .
In one of his lectures, I. P. Pavlov said that "to some extent the
vagus nerve is the nerve of rest, the nerve that regulates cardiac
rest."l Slowing of the cardiac rate may depend on the reflex or tonic
influences emanating from the vagus nerve center . In developing this
position of Pavlov, A. I. Smirnov and co-workers (Ye. Turbina, I. D.
Olefirenko and V. F. Shirokiy, 192U, 1926, 1927, 1929) divide animals
into groups: those possessing pronounced vagus nerve center tone, those
with weak tone, and those with no tone at all. Man, dogs, and hares be-
long to the first group. Animals like rabbits, puppies up to 3 weeks
old, and frogs have very weak tone or none at all.
Strong tonic excitation of the vagus nerve center that develops in
dogs with age prevents reflex slowing of the cardiac rate (I. A. Arshav-
skiy, 1951).
High tone of the vagus nerve centers makes prolonged muscular exer-
tion possible (man, dogs, horses, and hares). Such exertion is impossi-
ble for animals with weak tone (rabbits, cats), not to mention animals
with no tone (frogs). This view of the part played by high tone of the
vagus nerve centers in making prolonged physical exertion possible has
been confirmed by investigations, observations, and practices of sports
medicine.
Moderate sustained physical exertion (long distance running, bi-
cycling, ski marches, etc.), in which a state of relative equilibrium
^Collected Writings, USSR Academy of Sciences Publishing House, Vol. 5 >
p. 323, 1952.
425
develops between the rate of formation of disintegration products in the
body and the rate at which they are destroyed by oxidation, results in
slowing of the pulse —bradycardia at rest, increase in the systolic vol-
ume, and relatively low systolic blood pressure — and hypotention ranging
from 95 to 105 mm Hg (V. S. Farf el* , 19^1; M. Ye. Marshak, 19^6; A. N.
Krestovnikov, 195^; N. V. Zimkin, 1955).
During the first year of training, the pulse rate at rest, accord-
ing to Mitchell, averaged lh beats/min, the second year - 68, and the
third year - 53-
Our observations on a large number of participants in the All-
Eussian Sports Competitions in Moscow showed that a week before a meet,
the pulse rate in sprinters averaged 72 beats/min, middle -distance run-
ners - 66, and long-distance runners - 57, in 5 of whom it fluctuated
between hk and k6 (M. D. Chirkin, 192*0 . The reason for this reorgani-
zation of the autonomic nervous system seems to be that physical exercise
is accompanied by increased tone of the sympathetic nervous system, but
in the rest period this predominance shifts to the parasympathetic nerv-
ous system, thereby enabling man to function more efficiently. At the
same time the rhythm of cardiac and respiratory activity improves. We
also encountered such phenomena in our experimental investigations in-
volving the simulation of altitude meteorism by increasing pressure in
the cavities of the gastrointestinal tract (19^8-1955) •
These investigations were of comparative physiological nature, with
frogs, dogs, and human beings the subjects. Those on dogs involved their
breathing both atmospheric air and gas mixtures deficient in oxygen (cor-
responding to altitudes of 6000 and 8000 m above sea level) .
In the experiments on frogs under these conditions, we observed
marked impairment of the cardiac rate to the point of temporary cardiac
standstill. These pronounced interoceptive reflex influences on the
heart, recorded by mechanograms and electrocardiograms, were obviously
caused by insufficient tonic excitation of the vagus nerve centers in
the cold-blooded animals because they were relieved by administering at-
ropine .
In chronic experiments on dogs, reflex changes in cardiac and res-
piratory activity were less pronounced, although they became intensified
after oxygen deficiency.
In the experiments on human beings, moderate stimulation of the
mechanoreceptors of the stomach or large intestine (pressure in a bal-
loon of about 20 mm Hg) failed to elicit any significant reflexes to
respiration and cardiac activity, being manifested only after high pres-
sures (impairment of the respiratory rhythm, sinus arrhythmia of cardiac
contractions) .
426
Thus, the higher an animal is on the phylogenetic ladder and, there-
fore, the stronger the tone of its vagus nerves, the less disagreeable
are the interoceptive influences (such as altitude meteorism) .
Our findings agree with those of K. M. Bykov, V. N. Chernigovskiy,
P. P. Goncharov, V. A. Lebedeva, and others.
The same phenomena occur in air or motion sickness. The symptoms
of dysfunction in airsickness are due mainly to increased tone of the
parasympathetic nervous system. This condition is known to arise when
the analyzers sense periodic changes in body position (due to tossing,
bumpiness, yawing, etc.). This is the basis of V. Ya. Voyachek's oto-
lith theory of motion sickness .
Suitable physical exercises may mitigate the effect of these reflex
influences and this, in turn, helps to restore the dysfunction that
arises even in the latent form of motion sickness (rolling motion with
acceleration of 0.15 g) • The disturbances affect visual acuity, upward
shift of the dark adaptation curve, etc. (V. I. Kopanev, 1961) .
Motion sickness is prevented or treated by a wide variety of drugs
that decrease the tone of the parasympathetic nervous system, thereby
providing symptomatic relief (Kevil, 193^j Smith, 19kQ; Rolling et al.,
I9W-; D. M. Gorodinskiy, 1930; I. Ya. Borshchevskiy, 1937, 1939; and
others) .
This may seem to contradict the views we set forth above. However,
the favorable effect resulting from the use of drugs may be due not only
to inhibition of the parasympathetic nervous system centers but to some
other factor. Evidence of this comes from experiments aimed at activat-
ing the functions of the reticular substance by the administration of di-
bazol ( 2 -benzylbenz imidazole hydrochloride) (V. I. Kopanev, 1961) .
It is our intention to perform a series of experiments on the role
played by the brainstem reticular formation in heightening the tone of
the parasympathetic nervous system during physical training designed to
increase endurance. It seems to us that this approach to scientific
physical preparation of pilots and astronauts deserves careful consider-
ation.
Conclusions
1. Physical exercises that increase endurance result in intensified
parasympathetic tone .
2. With intensified parasympathetic tone, resistance increases to
unfavorable and unusual' environmental agents .
k2l
3. It follows, then, that in devising a program of physical prepa-
ration of air pilots and astronauts, considerable attention should he
paid to increasing their endurance.
EFFECT OF BRIEF PHYSICAL TRAINING ON THE SURVIVAL OF WHITE RATS
KEPT UNDER CONDITIONS OF PROLONGED HYPODYNAMIA AND ISOLATION
V. A. Shkurdoda
Activity of the neuromuscular apparatus is a prerequsite of the
normal development and existence of the human organism. Recent investi-
gations have shown that limiting motor activity decreases the competence
of the motor apparatus, impairs the accuracy of perception of kinesthetic
stimuli, and lengthens the period of complex and simple motor reactions.
Prolonged immobility has a marked effect on the subjective sense of well-
being and sharply reduces efficiency.
The purpose of this investigation was to determine the specific ef-
fect of systematic training on tolerance of hypodynamia and isolation
and in so doing to ascertain the degree of resistance to ionizing radia-
tion in animals subjected to various motor regimes.
Experiments were performed on white male rats . The experimental
animals were kept for 20 days in small solitary cells that prevented them
from moving about. Food and water were placed in specially constructed
boxes in such a manner that the animals could eat without getting out of
the cells. Hygienic conditions were strictly observed in attending the
rats.
The control rats were placed in an ordinary cage that was large
enough to enable them to jump, run, rest on their hind paws, lie
stretched out by themselves, or occupy any corner and bunch together
when sleeping.
Rats from each of the experimental groups were kept in solitary
cages for 20 days continuously.
The rats of the first group were taken out of the cages daily for
30 minutes and immediately actively trained on vertical poles.
The rats of the second group were transferred at this time for 30
minutes to a more spacious cage (passive rest) .
428
The rats of the third group were left to sit in the cages during
the 20 days.
Both the training and the passive rest were carried out daily for
the 20 days at the same time of the day.
After the 20 days of hypodynamia and isolation, all four groups of
rats were x-irradiated with a dose of 750 r.
During the experiments the animals were kept under observation in
order to study the effect of prolonged hypodynamia and isolation and
then their tolerance of radiation sickness.
Survival of the animals after irradiation was observed for 20 days.
Measurements were made before the experiment, during hypodynamia
and isolation, before irradiation, and during radiation sickness until
the end of the experiment.
Our investigations showed that the animals kept under the conditions
of hypodynamia and isolation exhibited varying degrees of tolerance, de-
pending on the amount of motor activity.
We concluded from analysis of the various indexes of motor and auto-
nomic functions that under the conditions of hypodynamia and isolation
vigorous muscular activity rather than passive rest is required to main-
tain resistance.
Observations on the first and second group of rats withdrawn from
their cages for training or for passive rest revealed a great variety of
behavioral manifestations by the animals allowed to move freely.
Physical training probably helps to ensure the equilibrium and mobil-
ity of the nervous processes, one of the factors in resistance to hypody-
namia and x -irradiation. Another important factor is the favorable ef-
fect of training on the interaction of the motor and autonomic functions
of the organism.
In the process of hypodynamia, 6 percent of the animals given brief
training died as compared with kl percent of the untrained animals.
The favorable effect of physical training on tolerance is due, in
our opinion, to the stream of proprioceptive impulses from the muscles,
which exert a tonic influence on the central nervous system.
As mentioned above, the survival rate of the animals kept in hypo-
dynamia and isolation but given training and passive rest was very high.
But the rats exposed to irradiation after hypodynamia were found to
429
possess varying degrees of resistance to this powerful stressor. The
most resistant were the animals given brief active training. The animals
allowed passive rest under the conditions of hypodynamia were the least
resistant.
The training exerted a vigorous mobilizing effect on the reflex and
other vital mechanisms concerned with maintaining bodily resistance to a
great variety of unfavorable factors. Thus, hypodynamia and isolation
were unable to disrupt the connections firmly established by training nor
did the powerful stressor (irradiation) subsequently applied have a de-
structive effect on most of the animals in this group. This assumption
is supported by the weight stability, blood picture, rate of reactions,
and body temperature noted in the trained rats.
Our investigations of animals amplify our knowledge of the effect
of physical training on human beings who work under conditions of limited
mobility and isolation. The results of our investigations and those of
other authors indicate that purposeful physical training is of consider-
able value in increasing resistance to ionizing radiation. Two to three
times more trained animals kept under the conditions of hypodynamia sur-
vived than untrained animals .
The level of vital activity of the trained animals, judging by the
objective data, was higher at all stages of the investigation than that
of the untrained animals. Passive rest during hypodynamia and isolation
improved the survival rate, but the animals were less resistant to x-
irradiation.
EFFECT OF PARACHUTE JUMPS ON THE ADAPTIVE REACTIONS IN PERSONS
OF DIFFERENT AGE GROUPS
S. N. Shurgin and A. N. Mazin
Parachute jumping, according to the literature, is a complex neuro-
psychological task associated with marked changes in the autonomic func-
tions of the body. Each jump, even after numerous repetitions, entails
emotional stress. A specific characteristic of military parachute jump-
ing is that it is done under a variety of conditions, often unfavorable.
Moreover, it involves severe physical exertion both in the preparation
period and after landing.
The main purpose of this investigation was to study the effect of
parachute jumps from new types of aircraft on persons in different age
430
groups (27 men in 7 stages). It "began a day before a jump and ended the
second day afterward. In view of the familiar published data concerning
the influence of the emotions on cardiac activity and "blood composition
(Cannon, Bekhterev, and others), emphasis was placed on changes in car-
diovascular reactions and "blood composition.
After landing in a plane at the airport, the pulse rate of the sub-
jects was 80-110 beats/min. During preparation for the first jump, the
pulse averaged 87 beats/min, second jump - 100, third jump - 93-
While flying in the plane, there was a further acceleration of the
pulse to 90-120 beats/min. Averaging the figures for three flights, the
pulse rate was 95^ 9&> an< 3- 101 beats/min.
The pulse rate increased again when the parachutists opened the
hatch. The average for 3 groups was 112, 128, and 129 beats/min, but it
reached 130-1^0 beats/min in individual cases. The highest pulse rate
was noted as soon as the subjects landed, the average for three jumps
being 117, 130, and ikQ beats/min, and, in a few cases, 150-160 beats/
min.
Investigation of the blood showed an increase of 10,000 to 12,000
leucocytes after a jump. The number of segmented neutrophils rose to
70 to 75 percent, while the number of lymphocytes dropped to 18 to 20
percent. Investigation of heparin and prothrombin time (data of P. I.
Gvozdev) showed that the maximum ejection of heparin occurred before and
after jumps, resulting in an increase in heparin time and in a lowering
of the prothrombin index.
According to I. S. Balakhovskiy, the changes produced in the metabo-
lism of the adrenocortical steroid hormones by parachute jumps are indic-
ative of a pronounced reaction by the endocrine glands and comparable to
reactions to stress .
The results of a functional test — 3 minutes' running in one spot —
revealed the dynamics of arterial pressure and cardiac rate at different
stages of the investigation. Analysis of the data made it possible to
divide the subjects into two groups. The first included men under 30
years of age, those possessing more adequate adaptive reactions of the
cardiovascular system. The second group --men 30-^0 and older --exhibited
changes in cardiovascular reactions of less lability, which obviously
may result in less adequate adaptive reactions.
According to the electrocardiographic data, the functional changes
in the 30-to year old group were more pronounced and they tended to per-
sist into the restorative period. The systolic index increased by more
than 10 percent, a sign of functional incompetence. Moreover, sinus
arrhythmia and instances of atrial extrasystole were noted after jumps .
14-31
Investigation of the oculocardiac reflex and orthostatic test pro-
vided some information on changes in the tone of the parasympathetic and
sympathetic nervous systems. In some of the men under 30* no significant
fluctuations were noted in the tone of the parasympathetic nervous system
throughout the investigation. Sympathetic tone increased markedly from
the 1st to the k-fh stages (in the landing area) followed by a decrease.
In the others — the men over 30 — "the parasympathetic tone increased,
reaching a maximum in the hth. or 5th stage. The subsequent stages were
characterized by a decrease, although normal tone was generally not re-
stored by the 7th stage ( second day after landing) . The increase in
sympathetic tone was less pronounced in this group than in the other.
Investigation of maximum strength and time of holding arms in
a horizontal position with 2 kg weights showed that the changes were
most pronounced in the Vth stage, i.e., immediately after a jump. These
characteristics were generally restored on the next day.
Conclusion
The results of our investigation show that while preparing for a
jump, during flight in the plane, and after a jump from a new type of
aircraft, parachutists develop prolonged emotional stress accompanied by
more pronounced changes in physiological characteristics than they do in
the case of jumps under other conditions .
Some characteristics of the cardiovascular system and autonomic
nervous system in the older men are not completely restored by the 2nd
day after a jump. We therefore recommend that their workload be reduced
and routine activity be reorganized for the two days after a jump.
PHYSIOLOGICAL REACTIONS IN WEIGHTLESSNESS
Ye. M. Yuganov
Theoretical considerations and some experimental data show that in
weightlessness we must expect changes in function of the vestibular,
motor, and tactile analyzers, impairment of functional interrelations
and resultant developments of disagreeable sensations, changes in muscle
tone and in cardiovascular and respiratory activity. Experimental proof
that such changes can arise and a determination of the nature and inten-
sity of reactions under these conditions is of theoretical and practical
importance in predicting the efficiency of man during extended space
^32
flights and in improving the system of selecting and training astronauts.
Some questions cannot be answered without biomedical experiments carried
out during actual flights. But it is clear that much can be learned in
laboratory and airplane investigations.
We believe that data on the effect of brief weightlessness on ani-
mals and man can be properly extrapolated to conditions involving pro-
longed weightlessness in direct proportion to the number of experiments
that are performed and to the accuracy with which the main qualitative
functional changes are determined. This was the thinking that led to
the numerous experiments carried out in I96O-I962 dealing with the ef-
fect of brief weightlessness on animals and man.
Owing to the importance of determining the functional characteris-
tics of the vestibular analyzer and the physiological mechanisms respon-
sible for "space sickness", studies were made on the excitability of the
vestibular analyzer in weightlessness. Its function was evaluated from
its thresholds of excitability in response to a galvanic current and
from the intensity and nature of the vestibular reactions in man sub-
jected to strictly measured angular and Coriolis accelerations. It was
found that brief weightlessness gives rise to highly regular changes in
the indexes of vestibular reactions — the latent period before manifesta-
tion of the reactions lengthens while their intensity diminishes. This
is proven by the shortening of the period of postrotation nystagmus, de-
creased duration of the illusion of counterrotation, reduced intensity
of protective movements after angular accelerations, lengthening of the
latent period before the "illusion of swaying" arises, by an increase in
the minimum speed of correction causing the trunk to bend on exposure to
Coriolis accelerations, and, finally, by a regular rise in the thresholds
of excitability in response to a galvanic current.
These facts suggest that in weightlessness the excitability of the
receptors of the semicircular canals decreases rather than increases af-
ter angular or Coriolis accelerations. This cannot be due to the direct
effect of weightlessness on the semicircular canals, for the loss of en-
dolymph and cupula weight does not signify a loss of mass nor does it
cause changes in the inertia of the endo lymph.
It is reasonable to assume that the aforementioned phenomena are
determined by changes in the reciprocal relations between the semicircu-
lar canals and the otolith apparatus. The nature of the observed changes
indicates that impulses from the otoliths inhibit the semicircular canals
in weightlessness much more than they do under ground conditions. As a
result, there is a lowering of "excitability" of the semicircular appara-
tus of the vestibular analyzer. Control experiments showed that these
changes are the direct effects of weightlessness on the otoliths rather
than of preceding accelerations. We believe that weightlessness does
not lead to functional exclusion of the otolith apparatus, to a peculiar
^33
physiological delabyrinthization thereof. It seems, instead, to he an
unusual minus -stimulus for the otoliths.
If weightlessness, like some other stimuli, can be conceived of as
having the property of cumulation, the summation of the nervous processes
that it activates in the cortical and subcortical formations can probably
produce the symptoms of space sickness. This cannot be ruled out as one
of the main causes of the vestibular discomfort suffered by G. S. Titov
in his flight on the Vostok.
Characteristics of vestibular analyzer function in weightlessness
were reflected in the state and activity of several systems of the or-
ganism. Mechanographic and electromyographic investigations of intact,
decerebrated, and delabyrinthectomized animals as well as experiments
involving human beings demonstrated that the tone of the antigravita-
tional skeletal musculature may decrease in weightlessness. Suffice it
to mention that the amplitude of the biopotentials of the neck muscles
of man, which ranges from 130-180 mv under ground conditions, dropped
to 1*0-50 mv in weightlessness, and in some instances there were phenom-
ena resembling the picture of bioelectric silence. The value of the bio-
potentials of the femoral flexor in animals usually decreased in weight-
lessness 1.5-2.5 times below the original level. It was experimentally
demonstrated that the effect of weightlessness on changes in tone of the
the antigravitational musculature is much less pronounced when the ves-
tibular analyzer is excluded.
The significance of motor -visceral relations in the regulation of
cardiovascular and respiratory activity is well understood. It was
right to assume that in weightlessness changes in the motor sphere, par-
ticularly the decrease in tone of the skeletal musculature, may be re-
sponsible for the tendency for disagreeable physiological effects to be
manifested in the cardiovascular system too. Accordingly, it was impor-
tant to study the state of those indexes of blood circulation function
whose manifestation varies with tonic contraction of the muscles. It is
absolutely essential in this respect to determine venous pressure. Ex-
periments on animals showed that in weightlessness the value of venous
pressure in the right atrium and ventricle regularly decreases from the
original 0+5 mm Hg and +15+25 mm Hg, respectively, by 15-25 mm Hg. Anal-
ysis of the changes in nature of respiration showed that it is virtually
independent of the characteristics of respiratory function in weightless-
ness. The changes in venous pressure were found to be directly related
to a decrease in the tone of the skeletal musculature. The physiological
changes noted may have also been caused by direct reflex changes in the
tone of the venous blood vessels.
To elucidate the role of this mechanism, investigations were carried
out on the vessels of the fundus oculi, the functional state of which is
known to be almost independent of the tone of the skeletal muscles and
k3k
respiration. The method of calibrometry with photographing of the fundus
oculi was used to determine any increase in diameter of the retinal veins
in weightlessness over their original size. These investigations showed
that the changes observed in the venous system are determined "by dilata-
tion of the veins as a result of direct reflex influences from the gravi-
receptors and of indirect influence on the tone of the veins due to de-
crease in the tone of the skeletal muscles. The lack or indistinctness
of such changes in delabyrinthectomized animals shows that reflexes from
the vestibular analyzer play an important role in these mechanisms.
It is conceivable that in prolonged weightlessness changes in ves-
tibular analyzer function, muscle tone, and some characteristics of ve-
nous circulation may become more pronounced and thus affect human effi-
ciency. The creation of artificial gravity may well be one of the
important measures designed to enable man to function normally in space.
Relevant investigations on animals revealed that, on the basis of
postural reflexes and general motor activity, the artificial gravity
produced by accelerations of 0.3 g can be regarded as the minimum effec-
tive value needed to prevent weightlessness from having unpleasant ef-
fects on the motor reactions of animals.
EFFECT OF AIRPLANE NOISE ON MAN AND NOISE CONTROL MEASURES
Ye. M. Yuganov, I. Ya. Borshchevskiy, Yu. V. Krylov
and V. S. Kuznetsov
One of the most disagreeable of the many physical factors to which
man is exposed during airplane flights and on the ground is the noise
made by motors and airplanes. Pilots, engineers, and technicians, while
in the air or engaged in takeoff operations at the airport, are subjected
to noise whose intensity exceeds the threshold of pain (130 decibels).
The noise level of a piston engine or airplane is 108-120 db, that of a
jet engine or airplane 120-1 to db or more.
Depending on their duration, intensity, and frequency, sounds change
within broad limits and they may provoke a variety of reactions by the
auditory analyzer from weak and reversible phenomena of adaptation and
hearing fatigue to pathological conditions. After prolonged exposure or
weakening of the nervous system, these changes become more pronounced and
persistent as they assume the nature of a chronic process in the form of
hardness of hearing and deafness.
^35
The specific effect of noise with an intensity of 120 db is gener-
ally manifested in sensations of pressure and clogging of the ears.
Noise of l60 do can cause acoustic trauma.
The reactions to sound stimuli "by flying and technical personnel
differ. Many of the latter have a progressive, vague reduction of hear-
ing. Personnel at test stations have a more pronounced impairment with
a tendency toward rapid progression. Still others seem to have good
hearing despite many years of exposure to loud noise. All this indicates
that the nature, degree, and dynamics of hearing impairment are largely
related to the nature of the work and to the individual reactivity of the
auditory analyzer to noise .
Noise has an adverse affect not only on human hearing, "but on the
body as a whole, for it causes fatigue and decreases efficiency. There
are indications that noise stimulates the vestibular as well as the audi-
tory analyzer. It impairs visual acuity, respiratory rate, cardiac ac-
tivity, and blood pressure. It changes the size of the spleen and kid-
neys, reduces the number and amplitude of gastric contractions, and
increases gas exchange. After prolonged exposure to noise, people de-
velop insomnia, timidity, slowing of mental reactions, and inattentive -
ness.
It has been observed that persons whose work involves the testing
of jet airplane engines and getting planes ready for the takeoff some-
times develop after a long period of time disagreeable subjective sensa-
tions in the form of a ringing in the ears, poor hearing, fatigue, and
loss of efficiency. Nervous fatigue may afflict those with an unstable
nervous system. Noise has less of an effect on flying personnel because
they are in a pressurized cabin and use interphone headsets, hermetic
suits, and other sturdy protective devices.
The effect of noise is much less at airports than at jet engine
test stations. This explains why the workers at these stations complain
more about their irritation, ready fatigability, impaired efficiency,
sense of clogging of the ears, and poor hearing.
For effective control of auditory function in personnel exposed to
loud noise, they must be given, in addition to a preliminary examination,
a regular annual audiometric checkup to detect in time signs of hardness
of hearing and deafness. This is also important for flying fitness exam-
inations. It is highly desirable in acoumetry not to limit the test to
whispered speech and tuning forks; modern methods of audiometry should
also be used.
The personnel can no longer be protected by individual devices
(noise filters) because the absorbing property of most of the common de-
vices ranges from 10 to 12 db, which is insufficient for 130-l^K) db jet
engine noise.
h36
There are two ways of controlling noise: (l) installation of spe-
cial equipment, and (2) individual devices. Attention should be focused
on (l) for supersonic aircraft. There are two "basic methods of suppress-
ing noise. One is to use absorbers placed in the front and rear of the
plane. The other is to keep the plane inside the test hangar. The absorb-
ers can be mobile, stationary, or semistationary. Stationary and mobile
sound absorbers are effective for a total noise level of about 20 db.
Mobile absorbers may be placed anywhere in the test area. In the case
of stationary absorbers, the tail of the plane is moved into a sound-
absorbing box or tunnel. Special equipment is available for simultane-
ous testing of four airplanes with a single sound-absorbing device.
Besides technical equipment, individual devices are recommended.
One of the main reasons for the difficulty of the problem is that the
human ear is not equally sensitive to all sounds. Hence the require-
ments for noise suppressors are highly complex. It is impossible to de-
sign a universal device to afford protection from sounds that vary
greatly in frequency and intensity. Several types will be necessary, de-
pending on the noise level, working conditions, and individual needs.
As far as aviation is concerned, the following two methods of indi-
vidual protection are the most effective: (l) plugging of the external
auditory meatus, and (2) insulation of the entire parotid region from
noise by special devices.
In designing protective devices for engineers and technicians, one
must bear in mind that they work mostly at airports and test stations at
different times of the year and that the work continues for a few minutes
to several hours with short breaks. Three types of protection are recom-
mended for these people: (l) special helmets, (2) ear muffs, and (3)
plugs .
Individual protective devices and special equipment are not enough.
Efforts must also be made to reduce the noise of the source itself
(engine) .
It is a very good idea to reorganize the work routines for this
category of personnel, arranging the work day to include short rest peri-
ods in a quiet place. When designing airports and test stations, provi-
sion should be made for soundproof places where the personnel can relax.
Test stands should be equipped with special telephones to facilitate
communication. The soundproofing of existing test stations should be im-
proved, with rubber or wooden screening and mats used to reduce the ef-
fect of vibration.
h3l
EFFECTIVENESS OF CERTAIN METHODS OF SELECTING PERSONNEL
BY VESTIBULAR TESTS
Ye. M. Yuganov, S. S. Markaryan, I. I. Bryanov,
I. A. Sidel'nikov and R. A. Vartbaronov
When flying in a modern plane, man is exposed to angular, Coriolis,
and linear accelerations, which change various functions of the body, in-
cluding the activity of the vestibular analyzer. During flights two
types of vestibular reactions develop which may adversely affect the pi-
lot's efficiency and physical fitness: (l) illusions that make it diffi-
cult for the pilot to orient himself, and (2) vestibular -autonomic reac-
tions that cause a deterioration in his general condition. The methods
of vestibular selection used should make it possible to predict with
reasonable accuracy whether the aforementioned reactions will occur dur-
ing a flight. The idea of reflex interaction of the afferent systems is
the basis of the methods that we recommend. These methods are aimed at
detecting any tendency toward spatial illusions and at determining the
thresholds and intensity of vestibular reactions to the simultaneous in-
hibitory effect of stimuli from two analyzers (motor, visual, etc.).
A Method of Determining the Threshold of Vestibular Excitability and
Sensitivity to the Illusion of Banking
The examinee sits with eyes closed in a rocking chair with an un-
steady base. A pulse current with a frequency of 10 cps stimulates the
vestibular apparatus for 3 and 10 sec. If the body does not deviate,
the current is gradually increased (but no more than 3 ma) until the
body clearly tilts to the side opposite the labyrinth stimulated.
When determining the threshold of vestibular analyzer excitability
to a pulse current with simultaneous presentation of visual stimuli, the
examinee continues to sit in the chair and stare at a lighted 2.5 v bulb
located 60 cm from the center line at eye level. Note is taken of the
amount of current required to cause a sensation of banking toward the
stimulated labyrinth and a loss of balance. The strength of the inhibi-
tory influences from the visual analyzer in relation to the vestibular
analyzer is judged from the difference in amounts of current that pro-
voke the banking reaction in the subject when his eyes are closed and
when he is looking at the light.
The kymograph (oscillograph) recording shows the intensity of the
motor reaction that accompanies the illusion and serves as an objective
criterion thereof. Thus, the sensitivity to false sensations is charac-
terized by the current during a total exposure to the stimulus of 10 sec.
It normally ranges from 1.5 to 2.5 ma. Smaller values of the current
indicate a heightened sensitivity to illusions of banking during flight.
438
Method of Investigation on a Revolving Chair with an Unsteady Base
This test is intended to detect the capacity of the motor analyzer
to inhibit vestibular reactions following artificial impairment of the
functional interrelation between the analyzers of spatial orientation.
The subject, with eyes closed, is rotated to the right (10 revolutions
per 20 seconds), then 3 minutes later to the left. After each rotation
is halted, the chair is mechanically shifted to the unstable base. Mean-
while, the subject feels a loss of balance and impairment of spatial ori-
entation. In those persons who are inclined to suffer impairment of spa-
tial impairment during flight, the sensation of counterrotation is
pronounced. There is a loss of balance for 30 seconds or more with com-
plete disorientation in space and, for 10-15 seconds, occurrence of auto-
nomic reactions .
The aforementioned methods are recommended as means of determining
the predisposition of fliers to develop the commonest spatial illusions.
They enable one to predict (in 80 percent of the cases as compared with
25 percent for the old methods) the possibility of occurrence (and mecha-
nism of manifestation and inhibition) of illusions during actual flights.
It is urgent that an effective method be available to evaluate vestibular-
autonomic sensitivity. Accordingly, we devised the following techniques,
which are based on the cumulative and simultaneous stimulation of the am-
pullar and otolithic apparatuses of the vestibular analyzer.
Methods of Determining the Intensity of Autonomic Reactions to
Cumulative, Intermittent Exposure of the Vestibular Analyzer to
Coriolis Accelerations
The subject is first examined for spontaneous vestibular disorders
and for good tolerance of the "O.P. " test. While being rotated on a
Barany chair at the rate of l8o°/sec for 20 seconds, the subject, with
eyes closed, bends his head rhythmically to the side 16 times in 20 sec-
onds. When the chair is stopped, the subject is asked to hold his head
straight and open his eyes, after which he is checked for autonomic re-
actions (pallor, hidrosis, nausea). If none of these is present, the
investigation continues 1 minute later (rotation in the opposite direc-
tion) . If the tolerance is good, the next investigation is changed. Un-
der the same experimental conditions, the subject bends his trunk forward
8 times in 20 seconds. The interval between rotations should not be more
than 1 minute in length. If pallor, hidrosis of the facial skin, or nau-
sea appears during this time, the investigation is halted and the subject
disqualified. Marked protective movements with a total absence of auto-
nomic reactions are not a cause for blocking admission to flying school
since these reflexes are easily weakened by appropriate training. Those
persons are deemed qualified who readily tolerate the entire investiga-
tion.
h39
Another method is "based on determination of the intensity of auto-
nomic reactions to cumulative, intermittent exposure of the vestibular
analyzer to Coriolis accelerations. Sitting in a Barany chair, the sub-
ject is rotated at l80°/sec while moving his head backward and forward
35° • Note is taken of the time necessary for autonomic disorders to be-
come manifest. It differs from subject to subject, amounting in individ-
uals with high resistance of the vestibular analyzer to h-G minutes and
in individuals with marked sensitivity to 1-2 minutes.
Still another method is a 2-minute test for tolerance of the cumu-
lative effect of Coriolis accelerations. At first the so-called C (Cori-
olis) index is determined at a rotation speed of l8o°/sec by the
Voyachek-Khilov method. Then, against a background of steady, even ro-
tation of the Barany chair at l8o°/sec for 1 minute, the subject with
eyes closed sits up and bends over at a rate corresponding to the C in-
dex every 5 seconds at the doctor's order. The experiment is repeated
every 50 seconds with rotation in the opposite direction. Note is taken
of the autonomic reactions and subjective sensations.
The test, given to 200 subjects, showed that individuals capable of
readily tolerating 2 minutes of rotation can easily withstand swaying in
Khilov swings and 0.P.--10.
The three methods of investigating vestibular -autonomic sensitivity
described above are helpful in determining the latent forms of vestibular-
autonomic disorders that cannot be detected by any of the methods now
used in flying fitness examinations.
SENSORIMOTOR COORDINATION IN EXTENDED WEIGHTLESSNESS
IN ACTUAL SPACE PLIGHT
V. I. Yazdovskiy, I. I. Bryanov, L. I. Kakurin, Yu. V. Krylov,
and M. A. Cherepakhin
The flight programs of Vostok 3 and Vostok k called for a study of
the effect of extended weightlessness on sensorimotor coordination in
astronauts A. G. Nikolayev and P. R. Popovich. Appropriate laboratory
tests were made beforehand. According to the program, the men had to
take the following tests:
(l) The astronaut stretches out his hands toward some instrument in
the front part of the cabin. In doing so, he remembers the relative lo-
cation of hands and their position relative to the orienting instrument.
Then, closing his eyes , he has to count off 20 seconds after which he
kko
opens his eyes and gauges the position of the hands. The result is
noted with arrows in the log"book in case they deviated from the original
position. The extent of the deviation is given in centimeters.
(2) With eyes open and then closed, the astronaut draws with a pen-
cil a spiral containing 3 loops, a 5-pointed star in an unbroken line, 2
vertical and 2 horizontal lines. The hands, one of which holds the log-
book, the other the pencil, are outstretched.
The rationale of these tests is that in weightlessness, vestibular-
postural mechanisms are of importance in forming a motor habit. If im-
paired, they may affect sensorimotor coordination.
A series of experiments simulating space flight with performance of
the above-mentioned tests was carried out before the flights in a model
of the Vostok in order to be able to evaluate the results of the tests
taken during the flights themselves. There were also some tests in the
laboratory. The results were carefully written up and then compared with
the notations in the logbooks of Vostok 3 and Vostok k.
The comparatively simple first test was performed with approximately
the same accuracy on the ground and in weightlessness. In any case, even
the most critical comparison of the reports of the laboratory experiments
and the logbooks reveals no basis for regarding weightlessness as a fac-
tor with negative effect on the static tension of the human musculature.
Analysis of the results of the second test taken on the ground and
in space showed that all the subjects did better with their right hand
than with their left, which is understandable since they were all right-
handed persons. These differences, to be sure, were not the same for
the various subjects. In some of them, the results of drawing the spiral
and star and, to a smaller degree, the parallel and vertical lines, were
sharply different when vision was excluded. In others, the results of
the test taken with both the right and the left hands were more or less
the same .
Also noteworthy is the fact that execution of the second task varied
in quality from subject to subject. Some drew the figures very well,
while others did so poorly, especially the spiral and star. The differ-
ences noted when the second test was taken with open and closed eyes were
likewise quite pronounced in the different individuals, varying from poor
to very good.
A comparison of the results of the first and second tests taken on
the ground showed that weightlessness did not impair sensorimotor coordi-
nation. The figures drawn in weightlessness were actually better than
those drawn on the ground, an observation agreeing with the astronauts 1
reports. "All the tests," P. R. Popovich said, "were better in weight-
lessness than on the ground. I drew very well. My hand was very
kkl
steady. I pencilled straight lines, even with my left hand. The right
hand did exceptionally well."
A comparison of the results of the second test taken "by the astro-
nauts in weightlessness with those of the subjects who had the best per-
formance on the ground clearly showed that the quality of the astronauts'
drawings was no worse, indeed it was even better than that produced by
the subjects on the ground. Thus, with respect to both the background
data obtained on the astronauts in simulated space flight and the data
on the best subjects among those invited to participate in the investi-
gation, the results of the second test taken in the course of space
flight indicate that prolonged dynamic weightlessness has no appreciable
effect on sensorimotor coordination. This is also borne out by the ob-
servations of A. G. Nikolayev and P. R. Popovich. According to Popovich:
"I worked with eyes closed with all the switches. I tried to work in
the darkness. When you go into the shadows, you cover the illuminators.
Even when you strike with your hand wherever you wish. I am lying down,
but I know that the radio switches are here. I stretch out my hand and
turn it on."
"It is quite possible to work with equipment in weightlessness,"
Wikolayev declared. "Writing and drawing in weightlessness are just the
same as on the ground. All movements are coordinated."
Nor was any impairment of coordination in space flight noted in
astronaut G-. S. Titov who, as we know, experienced some vestibular-
autonomic reactions .
Thus, the special tests taken to reveal sensorimotor coordination,
the handling of spacecraft equipment, and the handwriting of the astro-
nauts show that weightlessness has little effect on sensorimotor coordi-
nation. However, it should be kept in mind that the facts recorded in
space flight did not relate to motor coordination at the very beginning
of weightlessness. At any rate, we were unable to discover any signifi-
cance that it may have had as a novelty factor. There is, however, some
reason to believe that the influence of novelty resulting from a modifi-
cation of gravity, that is to say, from reducing it to zero, is a fact
that warrants our attention. Note, for example, Popovich' s statement
that the novel sensation of weightlessness causes strain in working.
However, it was impossible to determine the duration or intensity of
this strain or its effect on efficiency during the flights of Vostok 3
and Vostok h.
kk2
RADIATION REACTIONS AND CHEMICAL PROTECTION OF ANIMALS
EXPOSED TO HIGH-ENERGY PROTONS
S. P. Yarmonenko, E. B. Kurlyan&skaya , G. A. Avrunina, Ye. S. Gaydova,
R. D. Govorun, R. L. Orlyanskaya, G. P. Palyga, V. L. Ponomareva,
V. I. Fedorova and N. L. Shmakova
The purpose of our investigations was to determine the immediate
and long-range effects on animals of exposure to 660 mev of protons gen-
erated on a OIYal synchrocyclotron, the relative biological effectiveness
(RBE) of which has been little studied.
It has been reported that the RBE of protons, as compared with X-
rays, judging by such indexes as mouse and rat survival rates and changes
in peripheral blood, was 0.5-0.6 (l, K, 5). The mutagenic effect of pro-
tons, as determined in an investigation of the rate of recessive lethals
in the sex chromosome of Drosophila, was close to that observed after ex-
posure to X- and 7-rays (h, 6). It has also been demonstrated that mice
can be chemically protected against the action of protons, and the value
of the oxygen effect in so doing was made clear. Finally, protons have
been found to exert a high blastomutagenic effect, with tumors discovered
in 50 percent of the rats that died or were sacrificed.
This report presents the data obtained in the following analysis of
the biological effect of protons and of chemical protection therefrom in
comparative experiments involving the use of the 7-rays of CO . The
method was described in detail in an earlier report (h) . The experimen-
tal animals were stockbred mice and rats and mice of the BALES and C-57B1
strains. All the figures were statistically processed.
Hematological and Cytological Analysis of the Effect of Protons
and 7-Rays on Hematopoiesis
In comparative experiments on mice receiving whole -body radiation
of 500 rad, the degree of injury to the hematopoietic organs was less
pronounced after protons than after 7-rays. The depression of hematopoi-
esis in the bone marrow and spleen of animals irradiated with protons was
shallower and shorter -lasting, and regeneration set in earlier.
This difference was particularly evident in the dynamics of the
characteristics of the peripheral red blood. 7-rays caused deep and pro-
longed anemia with a drop in the erythrocyte count to kh percent of the
original level and a decrease in the hemoglobin concentration to 51 per-
cent, whereas protons caused only a slight and temporary decrease in
these characteristics.
kk3
Similar differences were noted in the leucocytes, especially the
neutrophils. After irradiation with protons, lymphopenia was fairly
deep, hut less pronounced, although damage to the lymphoid tissue of the
spleen (from specimens and impressions) was substantial.
The results confirm the view that the state of the peripheral blood
does not reflect the true depth of radiation injury to hematopoiesis.
These results can be used in radiobiology only as data for general ori-
entation purposes .
The experiments on white mice were concerned with early destructive
changes in bone marrow (starting within a few hours of exposure), dynam-
ics of mitosis and cell kinetics with chromosomal injuries. Protons
caused a typical radiation degeneration of bone -marrow cells (most pro-
nounced after 3 hours) , inhibition of mitotic activity the first 5-12
hours, and injuries to the chromosomal apparatus (most pronounced after
12 hours, judging by the number of aberrant cells). Judging by all these
criteria, particularly the number of degenerating and aberrant cells,
there was a strict dose relationship in the 250-1000 rad range. The high
sensitivity and strict dose relationship of the aforementioned changes in
bone-marrow cells make it possible to use them for the purpose of biolog-
ical dosimetry.
In all three characteristics, the effect of "Y-rays was more pro-
nounced; the KBE of the protons = 0.5-0.7.
Preliminary injection of the mice with radioprotectors — S, P-
aminoethylisothiuronium (AET) , mercaptoethylamine (MEA) , and 5~
methoxytryptamine (5 -MOT) — reduced the number of degenerating and aber-
rant bone -marrow cells in proportion to the effect of these compounds on
the survival rate. A combination of MEA and 5-M0T was the most effec-
tive. It enabled 50 percent of the animals irradiated with a dose of
1900 rad to survive. We can thus safely assume that the mechanism of
chemical protection consists chiefly in a weakening of the primary radia-
tion injury and resultant stimulation of the processes of regeneration.
With fractional irradiation, the protective effect of these drugs was
sharply decreased or lost.
Effect of Protons on the Reproductive Function
In experiments on male mice of the BABL strain irradiated with 500
and 700 rad, reversible changes were noted in the weight of the testes
due to death and subsequent restoration of the germ cells. Histological
analysis of speciments using Vogt and Kouning's method revealed evidence
of the typical sterilizing effect of protons that has been described in
detail for other kinds of radiation. However, the biological effect of
the protons was less marked than that of the 7 -rays (0BE = 0.6-0.7) and
it was strictlv related to the dose.
hkk
The use of a variety of protectors did not prevent the sterilizing
effect of the protons, but it did help to reduce the loss of weight of
the testes and shorten the period of sterility.
The reproductive function was almost completely restored (disregard-
ing genetic aftereffects) within k-1 months of exposure to 1300-1600 rad
of protons in white mice protected with AET, MEA, 5-M0T, or cystamine.
The first generation of mice (290 animals) produced by crossing protected
males with intact females developed with no apparent somatic injuries.
Analysis of Somatic Mutations Caused by Proton Irradiation
Using as a model the regenerating liver of white rats exposed to
single whole -body irradiation with 150 rad of protons or "i -rays, we
studied the resultant chromosomal injuries in the form of bridges and
acentric fragments appearing in dividing liver cells. Liver regenera-
tion was brought about by removing the large left and anterior right
lobes of the organ. The operation was performed 2h hours after irradia-
tion, and 30 hours after hepatectomy (during the first wave of increased
mitotic activity) the animals were sacrificed and specimens prepared.
The control animals were found to have 6.9 percent aberrant cells,
but after exposure to the protons and 7 -rays - 20 and 29 percent, respec-
tively. Thus, judging by the number of latent injuries to the chromo-
somal apparatus of the somatic cells, the protons were less effective
(RBE ^ 0.7).
Effect of Protons on Blood Protein Fractions
The method of paper electrophoresis was used to investigate protein
fractions in white rats 1, 3, 6, 10, 20 and 30 days after whole-body ir-
radiation with 500, 800, 1000 and ltoO rad of protons.
The changes in content of the protein fractions were most pronounced
during the first 10 days. The maximum deviations occurred on the 1st,
6th and 10th days, with a tendency toward normalization on the 3rd and
after the 20th day. The degree of deviation in content of the individual
fractions from the control values increased with the radiation dose.
The most characteristic changes --marked decrease in albumins and 1 -globu-
lins with increase in the other globulin fractions --took place the first
10 days after irradiation with doses of 800-1000 rad. Since the pro-
tein fractions were not completely restored by the 30th day of observa-
tion, protein metabolism was still impaired.
kk5
Long-Range Effects of Proton Irradiation
Further information was obtained on the high blastomutagenic effect
of protons. Of 85 rats examined, 39 were found to have tumors in differ-
ent sites and in 25 of these animals there were multiple tumors.
Experiments on stockbred white mice showed that although chemical
agents increased the animals' radioresistance, they did not prevent the
subsequent development of neoplasms. Of 65 animals that died quite some
time after irradiation with 1300-1500 rad of protons (preceded by the in-
jection of drugs), Ik developed leukemia and k had a sarcoma.
The results of our investigations provide new information on the
biological effect of high-energy protons that is useful for both theoret-
ical and practical purposes.
Translated for the National Aeronautics and Space Administration
by John F. Holman and Co. Inc.
I
"The aeronautical and space activities of the United States shall be
conducted so as to contribute . . . to the expansion of human knowl-
edge of phenomena in the atmosphere and space. The Administration
shall provide for the widest practicable and appropriate dissemination
of information concerning its activities and the results thereof."
— National Aeronautics and Space Act of 1958
NASA SCIENTIFIC AND TECHNICAL PUBLICATIONS
TECHNICAL REPORTS: Scientific and technical information considered
important, complete, and a lasting contribution to existing knowledge.
TECHNICAL NOTES: Information less broad in scope but nevertheless
of importance as a contribution to existing knowledge.
TECHNICAL MEMORANDUMS: Information receiving limited distri-
bution because of preliminary data, security classification, or other reasons,
CONTRACTOR REPORTS: Technical information generated in con-
nection with a NASA contract or grant and released under NASA auspices.
TECHNICAL TRANSLATIONS: Information published in a foreign
language considered to merit NASA distribution in English.
TECHNICAL REPRINTS: Information derived from NASA activities
and initially published in the form of journal articles.
SPECIAL PUBLICATIONS: Information derived from or of value to
NASA activities but not necessarily reporting the results of individual
NASA-programmed scientific efforts. Publications include conference
proceedings, monographs, data compilations, handbooks, sourcebooks,
and special bibliographies.
Details on the availability of these publications may be obtained from:
SCIENTIFIC AND TECHNICAL INFORMATION DIVISION
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
Waihin-jton, D.C. 20546
Live Music Archive
Librivox Free Audio
Metropolitan Museum
Cleveland Museum of Art
Internet Arcade
Console Living Room
Open Library
American Libraries
TV News
Understanding 9/11